GB2235857A - Spreader - Google Patents

Abstract

An apparatus for spreading particulate material on to a surface has a material hopper (1) with a discharge opening (3) adjacent and extending lengthwise of a driven roller (5) and through which material is deposited on to the roller. The hopper has a wall element in the form of a flap (17) extending to a location adjacent the roller external periphery and a vibrator having cam formations (21) causes oscillatory movement of the wall element, in use, in order to encourage material in the hopper to flow towards the opening (3). <IMAGE>

Description

SPREADER This invention relates to apparatus for spreading particulate material on to a surface and is particularly concerned with the spreading of top dressing onto a grassed surface, such as a golf or bowling green.

In one known form of spreader apparatus, material in a hopper falls onto a grooved driven roller which entrains the material and deposits it at a location beneath the apparatus so that material may be spread in a continuous layer on to a surface by movement of the apparatus thereover. Such an arrangement can operate satisfactorily with free-flowing dry material, but problems can arise when the material is damp, since it then tends to "bridge" across the hopper and either fails to fall onto the roller or falls thereon in a random uneven manner which precludes uniform spreading.

An object of the present invention is to provide an apparatus for spreading particulate material, such as top dressing, in which the aforesaid problem is minimised or avoided.

According to the invention, an apparatus for spreading particulate material onto a surface comprises a material hopper having an opening adjacent and extending lengthwise of a driven roller and through which material in the hopper is deposited on to the roller, the hopper having a wall element extending to a location adjacent the roller external periphery, and means for causing oscillatory movement of the wall element such as to encourage material in the hopper to flow towards said opening.

Conveniently, the wall element is hinged at a location spaced from the roller and is preferably engaged by vibrator means, typically in the form of a cam which may be fast for rotation with said roller, and operable to cause the oscillatory movement of the wall element.

The vibrator means may alternatively be driven by means other than the roller, such as an additional shaft extending, conveniently, externally of the hopper.

In a modified arrangement, an additional agitator is suspended from said wall element so as to rest in the hopper at a location angularly spaced around the roller from the edge of said wall element, the agitator moving with the wall element, during agitation of the latter, to provide additional agitation of said material at said location.

Preferably, said additional agitator is in the form of an elongate bar or the like, suspended, by flexible suspension means, from opposed laterally extreme locations on said wall portion.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a perspective view of part of one embodiment of the spreading apparatus of the invention; Figure 2 is a perspective view of part of a second embodiment of the apparatus of the invention; Figure 3 is a view similar to Figure 2 of another embodiment of the apparatus of the invention; Figure 4 is a view similar to Figures 2 and 3 illustrating a further embodiment of the apparatus of the invention, and Figure 5 illustrates a detail applicable to any of the illustrated embodiments.

The spreader apparatus illustrated in Figure 1 of the drawings includes a hopper 1 of generally funnel-like form into which material to be spread is introduced through a wide upper inlet opening 2 thereof for discharge through a much narrower outlet opening 3. The hopper 1 is mounted on a frame 4 which carries a metering roller 5 of which the outer peripheral surface has longitudinal ribs or ridges 6 between which are formed channels 7 for the reception of material to be spread.

The frame also carries a rotatable brush roller 8 of which the outer peripheral surface engages that of the roller 5, for the purpose to be described. A drive sprocket 9 is fast for rotation with the roller 5 and a drive pulley 10 is similarly secured to the brush roller 8. The frame carries also a hydraulic motor 11, intended to be connected, in use, to the hydraulic system of a towing tractor, and an output shaft 12 of the motor carries a drive sprocket 13. A drive element, in the form of a chain or belt 14 is passed around the aforementioned sprockets and pulleys and also around idler rollers 15 and 16, the arrangement being such that the motor 11 drives the metering roller 5 in the direction of the arrow A and the brush roller 8 in the opposite direction.The metering roller 5 governs the rate of spread of material, in that its speed can be set by the operator of the spreader apparatus by means of a valve in the hydraulic system of the tractor by which it is carried, in use. Of course the rate of spread of material is also governed by the tractor vehicle speed.

The opening 3 is formed generally laterally of the roller 5 and extends angularly over a substantial segment of the roller outer surface. The lower extremity of the opening is defined by a fixed edge 1A of the hopper and the upper extremity by the lower longitudinal edge 17A of a wall element in the form of a flap 17 which is pivotally connected to the remainder of the hopper along its upper longitudinal edge by a hinge 18. In practice, rubber seal strips 19, 20 (Figure 3) are secured respectively along those edges of the hopper and flap defining the opening 3 and engage the roller outer surface so as substantially to preclude unwanted leakage of material around the edges of the opening.Although the strips 19, 20 are shown only in Figure 3, it will be understood that they will be normally used in any practical construction embodying the invention, being omitted from the other figures for clarity of illustration. Secured to either end of the roller 5 are respective multi-lobe cam formations 21 each, in the case illustrated, having five cam lobes 21A. The flap 17 rests upon the cam formations 21 which, in this embodiment, lie within the hopper 1.

The spreader apparatus described above is normally carried, in use by a suitable tractor vehicle and arranged with the opening 3 directed towards the ground.

The hydraulic motor 11 is connected to and driven by the hydraulic power supply of the vehicle. When it is desired to spread material from the hopper 2 on the ground, the vehicle is moved to traverse the spreader apparatus at a desired rate over the ground. The motor 11 is energised to rotate the metering roller 5 and brush roller 8 in opposite directions. Material collected by the metering roller in the grooves 7 and carried by this roller past the lower seal 20 is dislodged by the brush roller in the vicinity of the opening 3 and falls vertically downwards on to the surface being dressed.

Rotation of the roller 5 and the cam formations 21 in the direction of the arrow A causes the cam lobes 21A to engage the flap 17 in succession, causing it to perform a pivotal oscillation about the hinge 8 in order to agitate the material in the hopper which, even if damp and tending to clog, will be thereby dislodged so as to fall on to the roller 5 for entrainment towards the opening 3.

A typical rate of oscillation could be around 500 cycles/min.

The embodiment described in Figure 2 is essentially similar to that of Figure 1, but in this case the cam formations 21 are disposed outwardly of the frame 4 and engage cam followers 22 which are in the form of rods rigidly secured to the flap 17 and extending through slots 23 through the frame 4. The rods 22 carry freely rotatable rollers 22A which engage the cam lobes 21A. In all other respects, this embodiment is similar to that of Figure 1.

In the embodiment of Figure 3, the metering roller 5 is not provided with cam formations, but an external cam shaft 24 is provided running externally of the hopper 1 and driven from the chain 14 by way of a further pulley 24A. The cam shaft 24 is provided with cam formations 24B which engage hardened cam followers 25 secured to the external surface of the flap 17 to produce vibration in the flap, upon rotation of the cam shaft, for the purpose referred to above.

The embodiment illustrated in Figure 4 has an additional agitator in the form of a bar 26 extending longitudinally of the apparatus and suspended by suitable flexible elements, illustrated as chains 27, connected to lugs 28 rigidly attached to the flap 17. The bar 26 is located lower in the opening 3 than the edge of the flap 17 and agitates the material to prevent any clogging or bridging of material which may occur at this location after it has moved beyond the flap 17. It will be understood that the additional agitator 26, although illustrated in an apparatus similar to that shown in Figure 2, may equally well be applied to other illustrated and non-illustrated embodiments of the invention.

Figure 5 illustrates a modification which may be applied to any of the described embodiments, or any other embodiment using a flap similar to the flap 17. Lateral edge portions of the flap 17 are turned upwardly through 900 to form upstanding flanges 17A and a stepped plate 30 is secured to the internal wall of the frame 1 to form a slot or channel 31 which receives the upwardly extending flange 17A therein. This arrangement effectively forms a seal which substantially prevents material in the hopper from falling down between the frame 1 and the sides of the flap 17. The arrows in Figure 5 illustrate the oscillatory movement of the flap 17 for the purpose described above and it will be understood that the depth of the slot 31 is sufficient to enable this movement to take place without collision between the flange 17A and plate 30.

The number, shape and positions of the cams employed may be varied according to requirements. For instance, depending upon the rigidity of the flap 17, it may be necessary to provide an additional cam or cams along the spreader roller, although this may be avoidable by, if necessary, strengthening the free edge of the flap by attachment thereto of one or more reinforcing elements. Again, it would be possible to shape the spreader roller so that its own external surface serves as the necessary cam, rather than employing the separate cams described. The drive chain 14 may be replaced by an appropriate system of drive gears, or other suitable drive means. Although the flap is shown and described as hinged on the hopper, it would be possible to secure a resilient flap to the hopper in a non-pivoted manner and cause oscillation of the flap by vibrating the material thereof by any suitable vibrator means.

Claims (13)

1. Apparatus for spreading particulate material on to a surface, comprising a material hopper having an opening adjacent and extending lengthwise of a driven roller and through which material in the hopper is deposited on to the roller, the hopper having a wall element extending to a location adjacent the roller external periphery, and means for causing oscillatory movement of the wall element such as to encourage material in the hopper to flow towards said opening.

2. Apparatus according to Claim 1, wherein the wall element is hinged at a location spaced from the roller.

3. Apparatus according to Claim 1 or Claim 2 wherein the wall element is engaged by vibrator means operable to cause the oscillatory movement thereof.

4. Apparatus according to Claim 3, wherein the vibrator means is a cam.

5. Apparatus according to Claim 3 or Claim 4, wherein the vibrator means is fast for rotation with the roller.

6. Apparatus according to Claim 3 or Claim 4, wherein the vibrator means is driven by means other than the roller.

7. Apparatus according to Claim 6, wherein the vibrator means is driven by an additional drive shaft.

8. Apparatus according to Claim 7, wherein the additional shaft extends externally of the hopper.

9. Apparatus according to any one of the preceding claims, wherein an additional agitator is suspended from the wall element so as to rest in the hopper at a location angularly spaced around the roller from the edge of the wall element, the agitator moving with the wall element during agitation of the latter to provide additional agitation of the material at said location.

10. Apparatus according to Claim 9, wherein the additional agitator is in the form of an elongate bar or the like suspended by flexible suspension means from opposed laterally extreme locations on the wall portion.

11. Apparatus according to anyone of the preceding claims, wherein resilient sealing strips are carried respectively by those longitudinal edges of the articulated wall element and the hopper which define the hopper opening, said strips engaging the roller outer surface so as substantially to preclude unwanted leakage of material around the edges of the opening.

12. Apparatus according to any one of the preceding claims, wherein opposed lateral edge portions of the wall element are turned outwardly to form upstanding flanges which are closely received within slots in the apparatus frame to retain material within the hopper.

13. Apparatus for spreading particulate material on to a surface, substantially as hereinbefore described with reference to any one of Figures 1 to 4, modified or not according to Figure 5, of the accompanying drawings.