CA1083533A - Raised wearing rod protected rubber screening plates - Google Patents

Abstract

ABSTRACT
A screen plate for screening ores, the screen plate comprising a rubber screen having a plurality of apertures therethrough, the apertures being arranged in rows longitudinally of the screen. In order to protect the rubber screen protective wear resistant metal bars are provided between the rows of apertures, the bars being embedded in the rubber screen and extending above the surface of the rubber screen.

Description

~083~33 This invention relates to improvements in or relating to screen plates, and more particularly to screen plates which are used in the mining industry for separating various grades of ore and the like.
5. In the field of screening, particularly the screening of ores and the like, it has been found that a rubber screen of appropriate hardness has a very high resistance to abrasion and it is common practice to use such rubber screens in such screening applications. However it has been found, that in 10. use, if the material being screened has portions or p:ieces thereof of relatively large dimension that these larger dimension pieces tend under certain conditions to lacerate the rubber screen. This is felt is due to the fact that these larger portions are such that, during the screening operation, 15. due to their weight sufficient force is applied by these pieces as they contact the screen to cut through the surface of the screen and tend to lacerate the surface. This does not occur with smaller sized particles and pieces due to the fact that the pieces due to their smaller weight do not 20. have sufficient energy to cause the edges thereof to cut and lacerate the screens.
Thus it is an object of this invention to provide a screen which will retain the desired properties and screening effect of the rubber screen while minimising the laceration effect of 25. the larger pieces being screened.
Thus there is provided according to one aspect of the invention a screen plate for the screening of ores and the like, the screen plate including a rubber screen having

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. . ` ~ : ` " . ' . . , . ~.:, ,, ,, , .; ' . , 1~83S33 apertures therethrough to separa-te the larger pieces of ore from the pieces passing through the apertures, the screen plate being characterised by runner bars embedded longitudinally in the rubber screen and having their upper 5- surfaces spaced above the surface of the rubber screen whereby the rubber screen is protected from the larger pieces of or to be screened.
In order to more fully describe the invention reference will now be made to the accompanying drawing which shows 10. a screen in perspective.
Referring to the drawing the screen plate 1 comprises a rubber screen 2 having the holes 3 therethrough arranged in parallel rows along and across the screen. Longitudinal rows spacer bars 4 are provided to be upstanding from the 15. surface of the rubber screen, the bars 4 running longitudinally of the screen plate 1.
The bars 4 are preferably formed of a material having the appropriate abrasion resistance and for example could be cast 15-3 white iron runner bars having a width of 20. approximately one inch at the top thereof and preferably spaced about one inch above the surface of the rubber screen 2. The spacing apart of the metal bars, the hardness and abrasion resistance thereof, the size and the height of the bars above the surface can be varied depending upon the 25. particular application to which the screen is to be applied.
Thus by way of example only, the screen plate 1 could be 24" long and 12" wide, wi-th 18 holes in 3 rows of 6 holes, the holes being 2~" by 1 3/4", the rows of holes being separated by the runner bars.
30. Preferably the runner bars 4 are firmly attached .

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or keyed into the rubber screen 2 and the bars 4 could be moulded into the rubber screen 2 during the moulding and manufacture of the screen and the shape of the bars where they are embedded into the screen can be varied 5. so that the bars would be effectively keyed into the screen. In the example shown, the bars 4 are permanently attached to the rubber screen with the bars 4 having an enlarged portion emhedded in the rubber screen 2.
~lternatively the bars 2 could be such that they can be 10. readily replaced, for example by being slidingly fitted through a shaped keyway or other shaped slot in the rubber screen 2 so that the bars can be replaced if they become excessively worn and so prolong the life of the screen itself.
lS. The rubber screen 2 is mounted on a metal backing plate 5, and mounting holes 6 are provided through the ` rubber screen 2, and the backing plate 5 to allow mounting of the screen plate 1 in position. Preferably the backing f_~ plate 5 is a perforated mild steel backing plate. ~-20. Preferably also the bars 4 are slightly trapezoidal in sections, i.e. the upper surface is 1" in width, but that the bar~ taper slightly towards the surface of the rubber screen 2, to a width of 7/8" or 3/4", so that the tendency of any pieces to jamb or become wedged therebetween 25. is minimized, for if-they pass between the adjacent upper edges, then the pieces would not readily foul b~tween the bars.

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~1~83~33 Thus it will be seen that the bars will effectively carry and support the largest sized pieces and particles and will absorb the major portion of the impact of those pieces so that the larger pieces will not due to their 5. high eneray cut and lacerate the surface of the screen and the bars will quickly and effectively transfer the larger pieces off the end of the screen where they can be recycled through the crusher or the like.
Thus although one form of the invention has been f~ 10. described in some detail it is to be realised that the invention is not to be limited thereto but is to include any and all variations falling within the spirit and scope oL the invention.

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Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A screen plate for the screening of ores and the like, the screen plate including a rubber screen having apertures therethrough to separate the larger pieces of ore from the pieces passing through the apertures, the screen plate being characterised by runner bars embedded longitudi-nally in the rubber screen and having their upper surfaces spaced above the surface of the rubber screen whereby the rubber screen is protected from the large pieces of ore to be screened, upper adjacent edges of the said runner bars being spaced closer to each other than portions of the bars therebeneath.

2. A screen plate as defined in claim 1, wherein the apertures are arranged in rows along the length of the screen plate, the runner bars extending along the screen plate and situated between each. said row of apertures and adjacent each longitudinal edge of the screen plate.

3. A screen plate as defined in claim 1 or claim 2, wherein the runner bars are of wear resisting metal.