Classifying – separating – and assorting solids – Sifting – Elements
Reexamination Certificate
1997-03-25
2001-07-17
Nguyen, Tuan N. (Department: 3653)
Classifying, separating, and assorting solids
Sifting
Elements
C209S399000, C209S409000, C052S710000
Reexamination Certificate
active
06260711
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to apparatus for screening, separating or grading materials and in particular to a shielding device for protecting parts of the apparatus from material that may ingress into the apparatus. The shielding device is applicable for use in apparatus for screening, separating and grading ores or other like materials, and it will be convenient to hereinafter describe the invention in relation to this exemplary application. It is to be understood, however, that the invention is not limited to such apparatus.
BACKGROUND OF THE INVENTION
A variety of apparatus systems have been developed for screening, separating and grading ores. A preferred apparatus includes a plurality of screen panels which are fixed to a support frame whereby individual panels can be easily and rapidly removed and replaced when worm. Screening apparatus of this type, with which the invention is concerned, is of any suitable construction well known to those skilled in the art. In that regard, the apparatus will include a support frame typically constructed of frame members for providing underlying support for a screen surface. An array of screen panels are fixed to the frame to form a continuous screen surface. The screen surface may be flat or cambered such as in deck screen apparatus, or may be curved such as in a trommel or drum screen apparatus. Each screen panel is typically square or rectangular in plan shape, with an upper or inner screening surface for receiving ore to be screened and a lower or outer bearing surface that may bear on the underlying support frame members. Apertures extend through the screen panels between the screening and bearing surfaces to provide for ore screening and separation.
One fixing arrangement used in this apparatus is disclosed in Australian patent 654091. This patent discloses the use of an elongate U-shaped fixing member for securing to the support frame so as to extend longitudinally between side edge regions of adjacent screen panels. The fixing member has a pair of connection portions, with connection elements being provided along the outer side surfaces of the connection portions and the side edge faces of the screen panels. The connection elements of each connection portion and an associated screen panel interengage to hold the screen panels in position on the support frame. The connection portions are inwardly deflectable away from the side edge faces in order to disengage the connection elements and disconnect the screen panels from the fixing member. A retaining member is provided for extending along the fixing member in engagement with the connection portions to resist their inadvertent deflection, and thus maintain engagement between the connection elements.
Another system for fixing the screen panels to the support frame incorporates an elongate fixing member to which a pair of panels are able to be secured. The fixing member is securable to an upper surface of the support frame and is adapted to extend between and below facing side edges of adjacent screen panels. In this arrangement, each of these side edges of the panels include downwardly projecting connecting portions which are cooperable with an adjacent portion of the fixing member. The system further includes a retaining member which is engageable with the panels so as to clamp each connection portion between the fixing member and the retaining member such that each screen panel is secured to the support frame.
In use, the whole apparatus including the support frame and panels is vibrated so that the material is able to move across the screen surface. While these fixing systems are effective in retaining the panels to the support frame, fine grade material, commonly referred to as “fines”, is prone to ingress in between the component parts of the apparatus. These fines are highly abrasive and increase wear on the components. The panels and the fixing members are typically formed from a plastics material, such as polyurethane, and are consumables. Consequently the wear of the panels and fixing members is expected and is not a major problem. However the fines are also able to lodge in between the fixing member and frame members of the support frame and as the support frame is not a consumable, this can cause excessive wear to the screening apparatus.
Typically the support frame is formed from steel and the ingress of fines into contact with frame members can cause pitting of the steel which can accelerate corrosion of the frame. In an effort to prevent this, resin coatings have been applied to the vulnerable frame surfaces. However this approach has only provided a short term solution as over time, the fines wear through the coating.
SUMMARY OF THE INVENTION
An aim of the invention is to provide another solution to this problem.
In its broadest terms, the present invention provides a shielding device for a frame member in screening apparatus of the type having at least one screen panel securable to a support frame wherein the device includes an elongate body portion locatable between a screen panel and a frame member of the support frame and at least one projecting portion, wherein the body portion and the projecting portion provide at least one surface which, in use of the shielding device, extends below an edge region of the screen panel for collecting material that passes over or through that edge region and deflecting it away from the frame member.
Preferably the or each projecting portion is a skirt that projects from the body portion.
An advantage of the present invention is that in operation of the screening apparatus any fines which ingress through the fixing arrangement of the apparatus or the screening apertures of a screen panel overlying the support frame are deflected away from the support frame. A further advantage is that the shielding device is able to minimise the abrasive effects of the fines by deflecting the material out of the screening apparatus. Further, the shielding device can be manufactured and supplied as a consumable and if required can be easily replaced when the other consumables of the screening apparatus, such as screen panels and fixing members, are replaced.
The invention is described herein with reference to the screening apparatus in a normal use orientation wherein it has an horizontally extending screen deck frame, and terms such as “above”, “upward”, “downward”, “upper” and “lower” should be construed in the light of this orientation. However, it is to be understood that other orientations may be equally possible and that consequential changes in terms such as those above may be required in the light of those orientations.
Preferably the body portion includes means for retaining the shielding device over a frame member in the screening apparatus.
In one form, the screening apparatus includes a fixing member securable to an upper surface of a frame member of the support frame and wherein an edge region of the screen panel is adapted to be secured to the fixing member through an arrangement of inter-fitting projections and recesses. When used in this arrangement, the shielding device is adapted to extend below the fixing member and over the frame member to deflect material passing between the panel and the fixing member away from the upper surface of the frame member. Alternatively the shielding device may be an integrally formed part of the fixing member.
A shielding device according to the present invention is particularly suitable for use with a fixing system in screening apparatus that includes a fixing member that is fixedly locatable adjacent an edge face of a screen panel. However it is to be appreciated that the shielding device may be employed in other fixing arrangements, such as when a screen panel is adapted to overlay a fixing member.
In one form, the shielding device includes a retaining lug with which another part of the screening apparatus is engageable for retaining the device over a frame member. Preferably this lug upstands from an upper surface of the body portion. In this arrangement the retaini
Lettela Pty Limited
Merchant & Gould P.C.
Nguyen Tuan N.
LandOfFree
Shielding device for screening apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Shielding device for screening apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shielding device for screening apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2483553