GB2074832A

GB2074832A - Broadcaster

Info

Publication number: GB2074832A
Application number: GB8113504A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-05-02
Filing date: 1981-05-01
Publication date: 1981-11-11
Also published as: GB2074832B

Abstract

In a tractor-mounted machine for broadcasting seed, fertiliser and like materials, the distribution of material is confined to an arc of variable size and direction by control of an outlet aperture (5) in a plate (3) interposed between a hopper for the material and a rotary distributor (1). The outlet aperture (5) opens into a chute (23) mounted on the underside of the plate (3), the outlet end of the chute is surrounded, at least on its trailing side, by a baffle assembly (24) on the underside of the plate (3) and material from the chute (23) is prevented from leaving the distributor (1) otherwise than via the outer ends of the vanes (27) by providing peripheral walls (28) which extend from the trailing edge of each vane to a point just short of the outer end of the leading edge of the vane behind it. <IMAGE>

Description

SPECIFICATION Broadcaster This invention relates to machines for broadcasting seed, fertiliser and other granular or powdered materials discharged through an outlet at the base of a hopper onto a distributor which rotates about a substantially vertical axis and ejects the material onto the ground by centrifugal force.

In order to enable the distribution of the material to be confined to an arc of variable spread and direction and in order to provide for varying the rate at which the material is discharged from the hopper onto the distributor and therefore, the rate or intensity of distribution over a given arc, it has already been proposed, in British Patent Specification No. 785829, to interpose an apertured plate between the base of the hopper and the rotary distributor and to provide means which cooperate with the aperture in the plate to form a material outlet which is offset from the axis of the distributor in a place substantially perpendicular to said axis and shaped so as to cause the distribution of the material to be confined to an arc, said means including an element which is adjustable to vary the dimension of the outlet in a direction to alter the spread of the arc of distribution and the whole being angularly adjustable about the axis of the distributor so as to vary the radial disposition of the outlet in relation thereto and thereby alter the direction of the arc of distribution in relation to the machine.

Machines of this kind for use with fertilisers and seeds are usually mounted on agricultural tractors and the ability to control the spread of the arc enables the operator to compensate for the difference in characteristics of the materials required to be spread.

With the frequent introduction of new materials for spreading it is necessary to carry out periodic tests to ensure that the machines being produced exhibit a high degree of spreading accuracy over a wide range of spreadable materials and although over the years these tests have produced satisfactory results, the applicant has recently devised more sophisticated tests which have indicated certain hitherto undetected inaccuracies in the spreading pattern and it is the object of the invention to correct these inaccuracies and provide an improved degree of control of the spreading pattern.

To this end, according to one aspect of the invention, a chute arranged beneath the outlet in the apertured plate is adapted to direct material passing therethrough onto the distributor in a direction to assist the centrifugal action of the distributor vanes and to catch and return material deflected upward from said vanes.

According to a further aspect of the invention, baffles are provided on the underside of the apertured plate and partly surrounding the chute, to intercept material falling from the chute without being entrained by the distributor vanes and deflect it into the vanes.

According to yet another aspect of the invention, the outer edge of the distributor between successive vanes is formed with an upstanding wall which serves to intercept material not entrained by the vanes and deflect it into contact with the vanes before leaving the distributor.

A preferred form of the invention will be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a typical broadcasting machine to which the invention is to be applied; Figures 2 and 3 are perspective views from above and below of the arc control mechanism; and Figure 4 is a perspective view of the rotary distributor.

The broadcaster shown in Fig. 1 is adapted to be mounted on the three-point linkage of an agricultural tractor and includes a hopper for the material to be spread which rests at its lower end within an annular supporting socket carried by transverse and inclined members of a frame which is adapted to be secured to the arms (not shown) of a tractor hydraulic lift. At its upper end the frame is provided with means for confining the upper end of the hopper and at its lower end the frame carries mechanism, positioned directly beneath the annular seat for the hopper, for broadcasting the contents of the hopper over a controlled arc.

The broadcasting mechanism includes a rotary distributor 1 shown in more detail in Fig. 4, mounted on a shaft 2 driven from the power takeoff shaft of the tractor on which the broadcaster frame is mounted and extending upwards into the hopper.

A plate 3 is secured to the underside of the annular seat for the hopper and has an aperture 4 through which the shaft 2 passes and a rectangular aperture 5 controlled by a shutter 6 slidable radially of the distributor 1. The shutter 6 can be drawn outward by a lever 7 to leave an elongated slot 8 between the inner edge 9 of the shutter 6 and the adjacent adge 10 of the plate 3, which slot is offset from the axis of the distributor 1 when the parts are assembled in position, and extends across a sector of the circle described by the rotating distributor so that the material falling through the slot onto the distributor is ejected thereby in the form of an arc, the rate of intensity of distribution of which can be varied by inward or outward adjustment of the shutter 6.

The spread or length of the arc of distribution is varied by altering the length of the slot 8 and this is achieved by an angularly adjustable masking plate 11 of circular form with a part of its periphery cut away. The plate 11 is apertured at 12 to fit freely round the shaft 2 and is supported in its adjusted position by an arm 13 pivotally mounted at 16 on the plate 3 for movement about a substantially vertical axis and provided with a forked portion the lower limb 1 7 of which, in the closed position of the arm, engages beneath the masking plate 11 and the upper limb 18 of which is adapted to engage over the hopper seat.The lower limb 17 carries a plate 19 formed with slots 20 which are adapted to selectively receive a locating pin on the underside of the masking plate, dependent upon the position of adjustment of the latter, and the arm 13 is adapted to be held in its closed position by a spring 21 one end of which is adapted to be detachably secured to the outer end of the arm and the other end of which is anchored at 22 to the plate 3.

A chute 23 is provided on the underside of the plate 3 with its open upper end in register with and-large enough to accept all material passing through the slot 8 in its largest form, and with its lower end opening onto the distributor at a point offset from the shaft 2. The distributor is arranged to rotate in an anti-clockwise direction as viewed in Fig. 3 and the chute 23 is offset to the extent that its major axis intersects a radius from the axis of rotation of the distributor at an angle slightly greater or smaller than a right angle. This arrangement of the chute 23 ensures that material passing through the chute from the hopper is given a component of velocity in the direction of rotation of the distributor 1.

The chute 23 may be open on its side constituting the leading side, in the direction of rotation of the distributor and is preferably provided with an internal space or pocket (not shown) above the lower end of its trailing edge, which pocket aids in controlling turbulence in the grains by catching grains deflected back from the distributor and returning them to the vanes for spreading.

Partly surrounding the chute 23 on the underside of the plate 3 is a baffle assembly 24 having baffles-25, 26 which are designed to intercept material which has fallen through the lower end of the chute and has not yet been entrained by the vanes 27 on the distributor 1 and to deflect this material into the vanes before it can pass radially outward between the plate 3 and the distributor.

In addition to the baffle assembly 24 on the plate 3, the distributor 1 is now provided wjth its own baffle assembly in the form of peripheral walls 28 each of which extends from midway along the trailing side of a channel-section vane 27 to a point spaced from the outer end of the leading side of the following vane 27 in the direction of rotation of the distributor. The distributor, which has four vanes 27, is thus provided, between each pair of adjacent vanes, with a triangular tray which is closed around its entire periphery except for a portion adjacent the outer end of the trailing vane, through which material falling onto the distributor is ejected by centrifugal force, having been prevented from leaving the distributor at any other point on the tray by the peripheral wall 28.

The machine according to the invention has achieved a spread pattern of an accuracy hitherto unobtainable with tractor-mounted agricultural broadcasters. No adjustment other than that of the shutter is neccessary to accommodate either a light dressing or a heavy dressing of fertiliser and providing the tractor is driven along consistently parallel lines, the evenness of spread is maintained regardless of the width to which the machine has been set, up to a recommended maximum.

Claims

1. A machine for broadcasting seed, fertiliser and other granular or powdered materials, comprising a hopper or the like for containing material to be spread and provided with a material outlet at its lower end, a vaned distributor plate mounted beneath said hopper outlet to receive material discharged therefrom and rotatable about a substantially vertical axis to eject said material onto the ground by centrifugal force and means interposed between said hopper outlet and said distributor for controlling the flow of material therebetween in such a way as to confine the distribution of material to a given arc and control the rate or intensity of distribution over said arc, said means including a plate formed with an aperture which registers with the hopper outlet and provided with a chute arranged beneath said aperture and so formed as to direct material passing therethrough onto the distributor in a direction to assist the centrifugal action of the distributor vanes and to catch and return material deflected upward from said vanes.

2. A machine according to Claim 1, wherein said chute is open at the side thereof constituting the leading side in the direction of rotation of the distributor.

3. A machine according to Claim 1 or 2, wherein said chute is formed with an internal space or pocket above the lower end of its trailing edge, which pocket is designed to catch grains deflected back from the distributor and return them to the vanes for spreading.

4. A machine according to any one of Claims 1 to 3, wherein the underside of said apertured plate is provided with a baffle assembly which partly surrounds the outlet of said chute in order to intercept material falling from the chute without being entrained by the distributor vanes, and deflect it into the vanes.

5. A machine according to Claim 4, wherein said baffle assembly is of mainly arcuate form and extends around at least the trailing side of said chute.

6. A machine according to any preceding claim, wherein the outer edge of the distributor plate, between successive vanes, is formed with an upstanding wall which serves to intercept material not entrained by the vanes and deflect it into contact with the vanes before leaving the distributor.

7. A machine according to Claim 6, wherein each distributor vane is of channel-section form with its web portion on the trailing side of the vane and each upstanding wall extends from a point substantially midway along the web of one vane to a point near the outer end of the leading side of the following vane, in the direction of rotation of the distributor.

8. A machine according to Claim 7, wherein that part of the distributor plate between each pair of adjacent vanes constitutes a triangular tray which is closed around its entire periphery except for an opening adjacent the outer end of the trailing vane, through which all the material falling onto the tray is ejected by centrifugal force.

9. A machine for broadcasting seed, fertiliser and other granular or powdered material, substantially as hereinbefore described with reference to Figs. 1 and 2 taken with either Fig. 3 or Fig. 4 of the accompanying drawings.