GB2114414A - A spreader for granular and/or powdery material - Google Patents

Abstract

A spreader comprises a hopper (2) having outlets (17, 18) which can be closed to a greater or lesser extent by a slide (19). Material in the hopper flows, in use, through the openings (17, 18) to a distribution member (6). The slide is pressed into contact with the hopper wall by a spring-loaded support (23) which reduces the possibility of material penetrating between the hopper wall and the slide. The hub (42) of an agitator extends through a hole in the hopper wall, the clearance between the hub (42) and the hopper wall being taken up by a closing ring (45). <IMAGE>

Description

SPECIFICATION A spreader for granular and/or powder material This invention relates to a spreader for granular and/or powdery material such as fertilizer.

Fertilizer spreaders commonly comprise a hopper and a distribution member, the hopper having an outlet port through which the material can pass to the distribution member. A slide is arranged for movement overthe outlet port to adjust its free aperture.

According to one aspect of the present invention there is provided a spreader for granular and/or powdery material, comprising a hopper and a distribution member, the hopper having an outlet port through which the material can pass to the distribution member, the spreader further comprising a slide which is movable over the outlet port to adjust the free aperture of the outlet port, the slide being arranged between a wall of the hopper and a support which is mounted resilientlywith respect to the hopper wall.

In a spreader in accordance with the present invention, the slide can move resiliently with respect to the hopper wall owing to the resilient movability of the support. The support is capable of exerting sufficient pressure on the slide so that clearance between the slide and the support, which could adversely affect the operation of the slide, is avoided. It can thus be ensured, in addition, that the movement of the slide relative to the hopper wall and the position of the slide in contact with the hopper wall are maintained in a satisfactory manner.

Therefore, the movability of the slide will not be adversely affected by the spring pressure, since the spring exerts pressure via the support on the slide.

An advantageous embodiment is obtained when the support is annular. The support can then be arranged about a rotary axis, about which the slide can turn.

Preferably the support is arranged on at least one pin (preferably three pins) which is fastened to the hopper wall and with respect to which the support is movable. The pin may be provided with a screwthread and may pass through an opening in the hopper wall and through a tapped hole in a centering flange in a manner such that the centering rim can be rigidly fastened by the pin to the hopper wall.

According to another aspect of the present invention there is provided a spreader for granular and/or powdery material comprising a hopper, a distribution member to which the material can pass from the hopper, and a member which is disposed in the hopper and is connected with a shaft extending through the opening in the hopper wall, a closing ring being disposed between the hopper wall and the shaft and/or the hub, the closing ring being movable with respect to the hopper wall in a direction normal to the centreline of the hub and/or the shaft.

The shaft and/or the hub can thus extend with ample clearance through the hopper wall, which facilitates the construction and/or the mounting operation.

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a front view of a fertilizer spreader; Figure2 is an enlarged plan view of the bottom of the hopper of the spreader of Figure 1; and Figure 3 is an enlarged sectional view taken on the line 111.111 in Figure 2.

The spreader shown in the Figures is for distributing granular and/or powdery fertilizer, although it could be used to distribute other material.

The spreader comprises a frame 1 on which a hopper 2 is arranged. The hopper 2 has two outlet spouts 3 and 4which are disposed symmetrically with respect to a vertical plane 5 containing the longitudinal centreline of the device. Beneath each of the outlet spouts is arranged a respective distribution member 6 and 7. The distribution members 6,7 are fastened to shafts 8 and 9, which are rotatable in the frame. The frame is provided with coupling members 10 for connection to the lower lifting arms of the lifting device of a tractor, and with coupling members 11 for connection to the top rod of the lifting device. The spreader has a driving shaft 12 which can be coupled, for example by means of an intermediate shaft, with the power take-off shaft of the tractor for the purpose of driving the shafts 8 and 9 and hence the distribution members 6 and 7 in rotation.Transmission members (not further detailed) are provided between the shaft 12 and the shafts 8 and 9.

As is shown for the outlet spout 3 in Figures 2 and 3, each of the outlet spouts 3 and 4 has a bottom 16 having outlet ports 17 and 18. Beneath the bottom 16 there is a slide 19 by means of which the outlet ports can be optionally closed to a greater or lesser extent.

For this purpose the slide 19 is provided with a rim 27, which is coupled with an adjusting device in a manner not shown in detail. The slide 19 is a round plate which is coaxial with the rotary shaft 8, the axis of which is indicated at 20. The slide 19 fits around the periphery of a centering flange 21 and is movable relatively to it. On the face of the slide 19 away from the bottom 16 there is a support 23, which carries the slide 19. The support 23 has a supporting rim 24, which is arranged with ample clearance around the periphery 22 of the centering flange 21 and is in contact with the slide 19.The slide 19 has two passages 25 and 26 which are identical in shape and size to the outlet ports 17 and 18 and which are arranged with respect to the rotary axis 20 in the same manner as the ports 17 and 18 so that the passages 25 and 26 can be brought into full register with the ports 17 and 18. The outlet ports 17 and 18 and the passages 25 and 26 are located just beyond the periphery of the supporting rim 24, which is centered on the axis 20. The centering flange 21 is rigidly fastened to the underside of the bottom 16 by means of three pins constituted by screwthreaded bolts 30. The bolts 30 have each a contersunk head 31 located in countersunk holes 32.

The centering flange 21 has tapped holes 33 thorugh which the bolts 30 are passed so that the centering flange 21 is drawn against the underside of the bottom 16 by turning the bolts 30. The contersunk hole 32 of each bolt 30 is sealed by sealing material 34 disposed between the head 31 and the hole 32.

The bolts 30 protrude from the underside of the centering flange 21 and constitute carrying pins for the support 23. The support 23 has a number of holes 35 corresponding to the number of bolts 30.

The outer diameter of the bolts 30 is smaller than the diameter of the holes 35, and so are a clearance fit in the holes 35. The arrangement is such that the support 23 is movable in the lengthwise direction of the bolts. Each bolt 30 is surrounded by a washer 36 and a compression spring 37, which are located on the side of the support 23 away from the bottom 16.

A nut 38 is screwed onto the bolt 30, the spring 37 being located between the nut 38 and the washer 36.

The bottom 16 has an opening 41 centred on the rotary axis 20. The upwardly extending shaft 8 of the distribution member 3 extends through the opening, and is connected to a drivable member arranged inside the hopper. Only the hub 42 of the drivable member is shown, extending through the opening 41 and fastened to the shaft 8. The diameter 43 of the hub 42 is appreciably smaller than the diameter 44 of the opening 41. Around the hub 42 and the shaft 8 is a closing ring 45, which fits around the outer periphery of the hub 42 so that the hub and the closing ring are relatively movable. The closing ring 45 has a sleeve 46 extending parallel to and fitting around the hub 42. The closing ring 45 is movable in a groove 47 defined between the bottom 16 and a collar 48 of the centering flange 21.The groove has a diameter 51, which is considerably largerthan the outer diameter 52 of the closing ring 45 so that the closing ring 45 can move in the groove 47 in a direction normal to the axis 20. The groove 47 has a height 49 which exceeds the thickness of the closing ring 45. To permit the transverse movement of the closing ring, the outer diameter 50 of the sleeve 46 is considerably smaller than the diameter 44 of the opening 41.

For use, the spreader is hitched by means of coupling members 10 and 11 to the lifting device of a tractor. The shaft 12 is linked to the power take-off shaft of the tractor so that drive can be transmitted from the power take-off shaft through the shaft 12 to rotate the distribution members 6 and 7. Preferably the distribution members are rotated in opposite senses so that their adjacent parts move in a direction towards the side of the machine on which the coupling members 10 and 11 are located. The material to be spread is loaded into the hopper 2 and during travel of the spreader across the surface to be covered it is fed through the outlet ports 17 and 18 and the passages 25 and 26 to the distribution members 6 and 7 which spread the material by virtue of their rotation.

The amount of material fed per unit time from the hopper to the distribution members can be controlled by turning the slides 19 with respect to the respective bottoms 16. Thus the passages 25 and 26 will be in register to a greater or lesser extent with the outlet ports 17 and 18, the magnitude of the parts ofthe outlet ports 17 and 18 left free by the slides determining the rate of flow of material out of the hopper. Thus the amount of material to be spread per unit of surface can be regulated in dependence on the speed of travel of the spreader.

For an accurate setting of the free apertures of the outlet ports 17 and 18, each slide 19 should satisfactorily contact the bottom 16. It is furthermore importantforthe slide 19 to be readily movable even after the spreader has been out of use for some time.

In particular when aggressive or corrosive substances such as fertilizers have been spread, any material retained between the bottom and the slide might cause corrosion resulting in sticking of the slide with respect to the bottom.

In order to ensure satisfactory adjustment of the size of the free apertures of the outlet ports and a satisfactory displacement of the slide with respect to the bottom, the slide 19 is arranged between the bottom 16 and the support 23 which is arranged in a resilient manner. The support 23 is acted on by the springs 37 so that it exerts a force on the slide 19 in the direction towards the bottom 16. The presence of three springs around three bolts ensures a satisfactory, even pressure. Therefore the slide 19 will invariably be pressed into satisfactory contact with the bottom 16 forming part of the hopper wall.

If due to atmospheric conditions and/or the presence of aggressive substances, corrosive material and/or dirt has got in between the bottom 16 and the slide 19, the slide 19 can deflect against the tension of the springs 37. As a result the movability of the slide is practically always ensured, whilst any dirt between the slide and the bottom will be expelled by the movement of the slide. The tension of the springs can be adjusted by turning the nuts 38 about the bolts 30 so that the force by which the slide is pressed against the bottom can be adjusted. It is particularly advantageous for the slide 19 to be of stainless steel so that jamming of the slide 19 with respect to the bottom 16 due to corrosion is avoided, the bottom being made from normal steel sheet.A satisfactory operation of the support 23 is maintained when it is made from synthetic resin so that the slide 19 cannot stick to the support 23, for example, due to corrosion. The springs 37 are preferably made from non-rusting material, for example, stainless spring steel so that the spring effect is maintained. A satisfactory, correct contact between the slide and the hopper and hence an accurate setting of the size of the free aperture of the outlet ports are particularly advantageous when the two distribution members, as in the embodiment shown, by their directions of rotation and the location of the outlet ports shown in Figure 2, spread the material on the same strip of land in symmetrical relationship to the plane 5.

In order to facilitate the connection of an agitator in the hopper with the shaft 8 through the opening 41 so that ample tolerance is available for mounting the hopper with respect to the shaft the opening 41 is significantly larger than the diameter 43 of the hub 42. Satisfactory closure of the opening 41 is obtained by means of the closing ring 45, the sleeve 46 of which fits around the hub 42. The ring itself is located in the groove 47 so as to be movable at least substantially normal to the centreline 20 so that the closing ring constitutes a satisfactory seal for the opening 41 around the hub 42 and the shaft 8. It is particularly advantageous to make the closing ring 45 from non-rusting material. In this embodiment the closing ring is made from synthetic resin. The closing ring can thus not rust in the groove 47 and remains always movable within it.Thus jamming of the hub 42 in the opening 41 is avoided, while the closing ring ensures a satisfactory seal and drive of the agitator connected with the hub 42 by the shaft 8 is maintained, even in the event of slight movements of the hopper with respect to the shaft 8, for example, during travel across uneven soil with a fullyfilled hopper. An advantage is that the closing ring 45 may be rigid and be arranged with sufficient clearance around the hub to avoid wear of the closing ring and/or the hub, in contrast to the structure of a closing ring of resilient material applied with clamping fit.

Whilst various features of the spreader that have been described, and that are illustrated in the drawings, will be set forth in the following claims as inventive features, it is to be noted that the invention is not necessarily limited to these features and that it encompasses all of the features that have been described both individually and in various combinations.

Claims (10)

1. A spreader for granular and/or powdery material, comprising a hopper and a distribution member, the hopper having an outlet port through which the material can pass to the distribution member, the spreader further comprising a slide which is movable over the outlet port, the slide being arranged between a wall of the hopper and a support which is mounted resiliently with respect to the hopper wall.

2. A spreader as claimed in claim 1, in which the support is annular.

3. A spreader as claimed in claim 2, in which the support is disposed about a rotary axis about which the slide can be turned.

4. A spreader as claimed in claim 3, in which the centreline of the annular support coincides with the turning axis of the slide.

5. A spreader as claimed in claim 3 or 4, in which the turning axis of the slide coincides with the rotary axis of the distribution memberwhich is arranged beneath the bottom of the hopper.

6. A spreader as claimed in any one of the preceding claims, in which the slide is turnable about a centering flange which is rigidly secured to the hopper wall, and in which the support has a supporting rim extending around the periphery of the centering flange.

7. A spreader as claimed in claim 6, in which the support and the centering flange are located around a shaft of the distribution member and/or a hub fastened thereto passing through an opening in the hopper bottom.

8. A spreader as claimed in claim 7, in which a closing ring is disposed between the hopper wall and the shaft and/or the hub, the closing ring being movable with respect to the hopper wall in a direction at least substantially normal to the centreline of the hub and/or the shaft.

9. A spreader as claimed in any one of the preceding claims, in which the support is mounted on at least one pin secured to the hopper wall, with respect to which the support is movable.

10. A spreader as claimed in claim 9, in which the