IE63594B1

IE63594B1 - "A hopper grid"

Info

Publication number: IE63594B1
Application number: IE216690A
Authority: IE
Inventors: Malachy J Rafferty
Original assignee: Malachy J Rafferty
Priority date: 1990-06-15
Filing date: 1990-06-15
Publication date: 1995-05-17
Also published as: GB9111061D0; GB2244941A; GB2244941B; IE902166A1

Abstract

A hopper grid (1) has parallel grid bars (10) secured at their upper ends to a cross-bar (11) which is pivotally connected to a grid frame (6). Hydraulic rams (13) mounted between the grid frame (6) and the cross-bar (11) oscillate the grid bars (10) in a jolting action back-and-forth (C-D) when the hopper grid (5) is in a discharge position (B) to clear the bars of adherent material.

Description

A .Stopper grid The invention relates to a hopper grid for pre-separation of aggregate such as top soil, waste material, garbage or coal.

Such hopper grids are generally mounted on a base, which S may be the hopper itself, for movement between an operative position over the hopper and a discharge position closer to the vertical for discharging of material resting on. the grid bar®.

A disadvantage with such hopper grids is that material 10 which is caught between grid bars or which is sticky, as often happens when garbage is being handled, does not drop away easily. Xn this case the material must be manually removed, which task is time-consuming and reduces efficiency of the hopper grid.

IS The invention is directed towards providing an improved hopper grid to overcome these problems.

According to the invention, there is provided a hopper grid comprising means for mounting on a hopper, grid bars and movement means for moving the grid h&xs between an 2Ό inclined operative position and a asore steeply inclined discharge position, characterised in that, the hopper grid further comprisessa movable frame to which at least some of the grid bars are pivotally connected, the movement means acting on the movable frasse,? aad rocking neats «sted between the movable frasa and the pivotally connected grid bars ©nd comprising means for pivoting said grid bars with respect to the movable frame in a rocking action when in th© discharge position.

In one embodiment the rocking means acts on said grid bars 5 rat their upper ends, and the grid bars are connected to the movable frame substantially closer to their upper ends than their lower ends to provide a substantially larger sweep of the lower ends of the grid bars with respect to their upper ends during the rocking action.

Preferably the pivotally connected grid bars are connected to a cross-bar which is in tum pivotally connected to the movable frame.

Ideally the rocking means acts between the movable frame and a bracket extending downwardly from the cross-bar.

In one embodiment the rocking means comprises an hydraulic ram means .

In another embodiment the hydraulic ram means comprises a two-way hydraulic ram.

Ideally the movement means comprises an hydraulic ram.

According to another aspect the mounting means comprises a fixed base and the movement means is mounted between the fixed bas© and the movable frame.

The invent ion will be more clearly understood, from the following description of sone preferred embodiments thereof, given by way of example only with reference to the accompanying drawings in which:- 3 Fig. 1 is a diagrammatic representation of a hopper grid of the’ invention; Fig. 2 is aa elevational view os th® hopper grid; and Fig. 3 is a plan view in the direction of the arrow Ill 5 of Fig. 2, showing the arrangement of grid bars and frame.

Referring to the drawings, there is illustrated a hopper grid assembly of the invention, indicated generally by the reference numeral 1. For clarity, the hopper grid assembly 1 is illustrated in schematic form in Fig, I. In this embodiment, the hopper grid assembly 1 comprises a base 2 of box construction suitable for fitting to the top of a hopper. The .base 2 has splayed side walls 3 to facilitate reception of material such as garbage for separation according to size.

The assembly X comprises a hopper grid indicated generally by the reference numeral 5 having a rectangular frame 6 open on the lower side. The frame S has a pair of brackets 7 at the lower end for pivotal connection to the base 2. A pair of primary two-way hydraulic rams 8 are mounted between the base 2 and a pair of brackets 9 on the frame 6 for movement of the grid 5 between a lower, operative position shown by interrupted lines A and an upper discharge position B closer to the vertical, as shown in Fig. 1.

The grid 5 comprises a set of parallel grid bars 10 which are secured at their upper end to a cross-bar 11. The cross-bar is pivotally connected at a pivot joint 12 to the frame 6« A pair of two-way hydraulic rams 13 are mounted between the transverse bar of the frame 6 and downwardly-depending brackets 14 secured to the cross-bar 11.

In operation, the assembly 1 is mounted on the top of a hopper and when in this position, the base 2 would form the upper portion of a hopper for reception of material. As material is loaded onto the grid 5, only the smaller parts pass through the bars 10 to the hopper. Needless to say, th® spacing between the bars 10 is set according to the grading required. When larger parts have gathered on top of the grid bars 10, the hydraulic reaas 8 push the grid 5 to the discharge position B, as shown in Fig. 1, in which cas© the material is free to drop off the bars. It will be noted that the lower end ox the bars 10 are free and the frame does not extend across the bars at the lower end. Thus, there is an uninterrupted path for material to drop off the grid 5. However, in addition to this discharge action the hydraulic rams 13 are operated by a control mechanism to expand and contract quickly* This causes the cross-bar 11 and thus th© grid bars 10 to oscillate in a jolting action between a lower position C and aa upper position 0 as shown in Fig. 1» The jolting action is about the pivot joint 12 on the frame 6. It will be noted that because the bracket 14 is relatively close to the pivot axis through the pivot joints 12, a relatively short movement of the rams 13 is required to cause a relatively large sweep of the bars 10. This is illustrated clearly in Fig. 1. This jolting action of the bars causes sticky material or material which is wedged, between bars to drop away and thus considerably improves efficiency of clearing of the grid 5. This is of considerable importance when the material being handled is garbage, parts of which may adhere to the bars 10.

Not only does the invention considerably improve the efficiency of a hopper grid but it avoids the potential for accidents which would otherwise be caused by an operator manually trying to remove items from the grid bars 10. This is very important for safety, Needless to say, the invention is not limited to the embodiments described. For example, it is envisaged that not all of the grid bars may be actuated in a jolting action. Further, each grid bar may be independently oscillated with, respect to the frame and it is also envisaged that an actuating means other than a hydraulic ram may be used.

I Further, it is not essential that the grid bars be parallel and It is envisaged that cross-bars may also be included to form a mesh.

It will be appreciated that the invention provides & simple. inexpensive and effective solution to the problem of dislodging material from grid bars.

The invention Is not limited to the embodiments hereinbefore 5 described, but may be varied in construction and detail.

Claims

1. A hopper grid comprising means for mounting on a hopper, grid bars and movement means for moving the grid bars between an inclined operative position and a more steeply inclined discharge position, characterised in that, the hopper grid further comprises sa movable frame to which at least some of the grid bars ar© pivotally connected, the movement means acting on the movable frame; end rocking means mounted between th© movable frame and th® pivotally connected grid bars and comprising means for pivoting said grid bars with respect to the movable frame in a rocking position. action when in th© discharge 2. A hopper grid rocking means as claimed in acts on said claim grid 1, wherein the bars at their upper ends, and the grid bars are connected to the movable frame substantially closer to their upper ends than their lower ends to provide a substantially larger sweep of the lower ends of th® grid bars wjLth respect to their upper ends during the rocking action.

2. 3. A hopper grid as claimed in claims 1 or 2 wherein the pivotally connected grid bars are connected to a cross-bar which is in turn pivotally connected to the movable frame.

3. 4. A hopper grid as claimed in claim 3 wherein the rocking means acts between the movable £rame and a bracket extending downwardly from the cross-bar.

4. 5. A hopper grid as claimed in any preceding claim, wherein the rocking sears comprises as hydraulic ram means.

5. 6. A hopper grid as claimed in claim 5, wherein the hydraulic ram means comprises a two-way hydraulic ras.

6. 7 „ A hopper grid as claimed in any preceding dais, wherein the movement means comprises as hydraulic ram.

7. 8. A hopper grid as claimed ia elaiaa “ wherein the mounting means comprises a fixed base and the movement means is mounted between the fixed base and the movable frame.

8.

9. a hopper grid substantially as hereinbefore described, with reference to and as illustrated ia the accompanying drawings.