AU615786B2 - Screen elements - Google Patents

Description

i$ t7 C 1 cl: I- 1- COMMONWEALTH OF AUSTRf 1 5 7 Form 1s PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: PH 0093 Lodged: 29th August, 1988 Complete Specification Lodged: 00o Accepted: Published: °"Priority 00 0 S0 a 0 0a SRelated Art: 0 0000 o ,Nane of Applicant: 0 00 0 0~r 0 00 o Address of Applicant: Do a Actual Inventor: o oo 00 0 d 0 0 0 Service 0 Aadress for Service RICHARDSON PACIFIC LIMITED 330 Ballarat Road, Australia.

Braybrook. Victoria 3012.

KENNETH LESLIE DOUBLEDAY and KEVIN ARTHUR BUGDEN EDWD. WA.TERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: SCREEN ELEMENTS

US

The following statement is a full description of this invention, including the best method of performing it known to it- SQj832 25'8

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-2- SCREEN ELEMENTS This invention relates to screening panels and screening decks as used for the separation and grading of materials for example in the mining and quarrying industries.

Screen decks are subject to abrasion and wear which is often concentrated in particular zones of the screen deck so that replacement of the total deck may not be needed.

Australian Patent 482212 provided a screen panel with peripheral dependent protrusions having a shoulder so that adjacent panels had aligned shouldered protrusions which had an interference fit into holes in the supporting frame of the screen deck. The shoulders on the protrusions abutted the undersurface of the edges of the holes in the S015 frame to retain the protrusions and consequently the screen ol 5 elements. The screen elements according to patent 482212 were intended to be inserted by force e.g. hammering and to be removed by leverage.

In practice the time taken and the effort required to install and remove the screen panels according to Patent 482212 can be excessive. One attempt to provide a less o strenuous and less time consuming means of installation is taught in Australian Patent 517319. This patent modifies the screen panels of 482212 by eliminating the shoulder on the protrusions and providing grooves in the protrusions and pins which when inserted in the grooved protrusions distend them to retain the panels in the frame. This pin expanded fastening method is generally quicker and less strenuous o than the installation of panels according to patent 482212 but has the disadvantage of requiring more parts in the inventory and the possibility of losing the pins. Further the pins render the system more costly.

It is an object of this invention to provide a simple solution to the problem associated with assembling and removing the panels according to patent 482212.

To this end the present invention provides a screen panel for mounting on a grid like supporting frameL hi i 3 formed of apertured bars in abutment with adjacent screening panels which comprises a screening surface and a plurality of protrusions spaced along its periphery for insertion into the apertures in said bars of said supporting frame to form with the protrusions of adjacent screening panels composite protrusions wherein the outer peripheral faces of said protrusions have projections which are located on the protrusions to form a widening of the composite protrusions in the apertured bars to prevent displacement of the 10 screening panels during normal operating conditions.

i0 Although the screening panels of patent 482212 had ,I ~shoulders on the protrusions these were in the internal face of the protrusions to seat under the edge of the apertures S in the bars to prevent removal. In the present invention o0 o the internal face of each protrusion is preferably flat. By 0°15 providing a raised or projecting surface on the external ooo face the projections are splayed when they abut to form a eooo composite protrusion. The projection is located on the surface at a point below the lower edge of the aperture in 20 the bar frames. This ensures that the composite protrusions are deformed and widened to prevent displacement of the 4144 t screening panel during operation of the screening deck.

t t1 ,However this does not affect the ease of insertion or ease of removal because the panels can move relative one to the

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other there being no shoulder to resist movement past the "25 edge of the aperture in the frame bar.

The screening panels and screening decks of this o :i invention may be apart from the shape of the protrusions °o conventional in design and made from similar materials and to similar specifications as the screening panels and decks disclosed in patents 482212 and 517319.

A preferred embodiment of this invention will now be described with reference to the drawings in which figure 1 is a plan view and figure 2 a side view of a screening panel of this invention; figure 3 is a schematic t i illustration of two adjacent panels showing in detail the composite protrusion in the aperture of the frame, and i i'? /4 -4 figures 4, 5 and 6 are illustrations of preferred profiles for the protrusions and figure 8 is a detailed view similar to figure 3 of the profile of figure 7.

As seen in figures 1 and 2 the screen element 1 comprises a screening surface 2 with apertured portions 3 for the screening of mined material. The peripheral protrusions 5 exhibit a raised external surface portion 6.

As seen in figure 3 abutting panels 1 and 1' and abutting protrusions 5 and 5' form a splayed composite protrusion which is widened below the aperture in the frame 9.

Figures 4A and 4B shows a profile and front view of the protrusions of figures 1 to 3. Further embodiments are shown in figures 5A and 5B and 6A and 6B.

In each case the protrusions are cut away in the portion adjacent the aperture in the bar to assist in deformation of the composite protrusion. However, this is not an essential requirement.

The longer protrusions provide a longer contact surface for the two protrusions forming the composite protrusion.

In the embodiment of figure 7 the protrusions 6 t 4 t have a projection wnicn is serratea to enable oppuseu projections 7 and 7' as shown in figure 8 to interlock.

This is particularly useful where the material used to form the protrusions has its surface friction reduced when wet.

Any suitable profile may be used for the serrated surface.

From the above description it can be seen that the present invention overcomes the problem associated with the prior art without having recourse to additional integers such as pins.

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Claims (4)

1. A screening panel for mounting on a supporting frame having apertured bars in abutment with adjacent screening panels, said screening panel comprising a screening surface and a plurality of dependent protrusions spaced about its periphery for insertion into said apertures in said bars of said supporting frame to form with the protrusions of adjacent screening panels composite protrusions, where in the outer peripheral faces of said protrusions have projections which abut with projections on the protrusions of adjacent panels to form a widening of the S composite protrusions in the apertured bars to prevent displacement of the panels during screening operations.

2. A screening panel as claimed in claim 1 wherein protrusions are provided on two opposed edges of the screen 4oo panel.

3. A screening panel as claimed in claim 1 wherein each projection is located adjacent the lower end of each protrusion and is convexly profiled.

4. A screening panel as claimed in claim 1 wherein the 1 r projections are shaped so that frictional resistance between abutting projections is increased. DATED this 6th day of July, 1989. S t ,RICHARDSON PACIFIC LIMITED WATERMARK PATENT TRADEMARK ATTORNEYS, Queen Street MELBOURNE. VIC. 3000 AUSTRALIA DBM:jl(8.8) 1. L ,t *sL_