Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
  • B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
  • B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
  • B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
  • B07B1/4645—Screening surfaces built up of modular elements

Definitions

• the present invention relates to a screen with overlapping elongate screen cloth elements.
• Screens and screen cloth elements of this type are extensively used and are known e.g. from SE-B- 60340 and PCT publication WO9611070. These screens comprise a screen frame and successively mounted and mutually overlapping screen cloth elements.
• the screen cloth elements are at one end secured to the screen frame by snap lock means, the other end of the screen cloth elements being clamped between the screen frame and a portion of the following screen cloth element provided outside the snap lock means.
• One part of the snap lock means projects from the underside of the screen cloth element, whereas the other part of said snap lock means is arranged at the upper edge of supporting elements included in the screen frame.
• the screen cloth elements are elongate with a length of about 50 cm and a width of about 30 cm. In some embodiments these elements have a length of about 100 cm and a width of about 60 cm.
• a major advantage of these screens, as well as the screens according to SE-B-422418 and its counterpart US-A-4, 141, 821, is that the separate screen cloth elements can be exchanged when worn to a greater extent than other screen cloth elements in the same screening device.
• the screens according to SE-B-422418 have the advantage of being considerably easier to mount and dismount, even when a separate screen cloth element in the centre of a large screening surface is involved.
• the screens and screen cloth elements according to SE-B-460340 and WO9611070 function well if they contain a rigid reinforcement frame. In some screen applications it is, however, desirable to use elongate screen cloth ele- ments, which are unreinforced or reinforced with flexible reinforcement material. However, the above-mentioned prior art screen and screen cloth design according to SE- B-460340 and WO9611070 does not function in a completely satisfying way in such screen applications.
• the rigid reinforcement frame is generally made of metallic material, in particular steel, which can cause difficulties from the point of view of recycling.
• one object of the present invention is to provide a screen and a screen cloth element of the elongate type as disclosed in SE-B-460340 and WO9611070, which could be formed of an unreinforced elastomeric material or of an elastomeric material reinforced with flexible reinforcement material, while maintaining the advantageous characteristics of this screen or this screen cloth element.
• each screen cloth element has additional snap lock means at least at one location between the upstream and the downstream ends .
• the one part of these additional snap lock means projects further from the underside of the screen cloth element than the part of the snap lock means positioned at the downstream end of the screen cloth element in order to be able to extend downwards between guide means included in the screen frame.
• the other part of the additional snap lock means has the form of a strut element extending between said guide means.
• DK-B-145528 and its counterpart EP-0062675-B2 disclose a screen, which has a supporting grate consisting of two layers of intersecting bars arranged at different levels, square screen cloth elements being secured to the upper layer of bars by the underside of the screen cloth elements having guiding grooves of such a depth that the screen cloth elements in their mounted state abut against the upper side of the bars in the lower layer of bars.
• the guiding grooves are formed with such a profile that after assembly the guiding grooves will engage the upper layer of bars in the supporting grate by snap lock action.
• Fig. 1 is a schematic perspective view of an example of a screen with screen cloth elements according to the present invention.
• Fig. 2 is a bottom view of a screen cloth element.
• Fig. 3 is a section taken along the line III-III in Fig. 2.
• Fig. 4 is a longitudinal section through a portion of the screen.
• Fig. 1 shows schematically a screen with a screen frame 10 having transverse supporting beams 11.
• Longitu- dinal screen frame elements 12 are secured to these transverse supporting beams.
• These longitudinal screen frame elements 12 in turn support transverse strut elements 13, 14.
• the strut elements 14 are secured at a lower level than the upper edge of the screen frame elements 12.
• the strut elements 13 are L-shaped and arranged in such a way that their upper edge is located at a higher level than the upper edge of the screen frame elements 12 and one of their legs forms an abutment surface 15.
• the strut elements 13 can, however, have a different shape, and the abutment surface 15 can be formed on a separate, transverse element in the screen frame 10.
• Elongate screen cloth elements 16 are mounted in the screen frame by snap lock means, whose one part is formed by the strut elements 13, 14.
• the strut elements 13 have a thickened portion 23 at their upper edge.
• the strut element 14 consists of a round bar, whereas in the embodiment of Figs 2 to 4, it has the form of a flat iron bar with a thickened portion 24 at its upper edge.
• the other part of the snap lock means is formed by snap lock recesses 17 in transverse ribs 18, 19 on the underside of the screen cloth elements.
• the rib 18 positioned nearest to the downstream end B i.e.
• the screen comprises, however, at least one additional snap lock means between the ends of the screen cloth element.
• additional snap lock means which include the ribs 19 with the recesses 17 and the transverse struts 14.
• the number of additional snap lock means depends on the length of the screen cloth element. Thus, one, two or even more additional snap lock means can be used.
• the screen cloth elements are preferably made of elastomeric material, preferably polyurethane . Combinations of different types of elastomeric materials can also be used, e.g. rubber and polyurethane.
• elastomeric materials e.g. rubber and polyurethane.
• cord material or bars of organic material in particular polyester, polyamide or polyaramide material.
• glass fibre material is used as flexible in- organic reinforcement material.
• a further improvement of the function of the screen cloth elements can be obtained if reinforcing inclined supports 21 are formed on one side or on both sides of the ribs 18, 19.
• the screen cloth elements are formed with longitudinal reinforcement ribs 22 which are disposed at least on the long side edges of the screen cloth elements and which project from the underside of the screen cloth elements and are bevelled, such that after assembly they can rest on the upper edge of the longitudinal screen frame elements 12.
• longitudinal reinforcing ribs 23 can, however, be formed in other places as well between the long sides of the screen cloth elements.
• the screen cloth elements When mounting the screen cloth elements on the screen frame, the screen cloth elements are mounted successively, so that one upstream end of the screen cloth elements is inserted under the projecting portion 20 of superjacent screen cloth elements in order to be secured between this and the subjacent abutment surface 15. Subsequently, the screen cloth element is successively pressed downwards to be secured to the screen frame also by the additional snap lock means 14, 17, 19, 24. The screen cloth element nearest to the upstream end of the screen is clamped in prior-art manner to the screen frame by means of a trans- verse hold-down strip 25.
• the separate screen cloth elements 16 have through- holes, whose form depends on the type of screening work to be performed. Thus, the form and size of the holes can be varied without departing from the idea of the invention.

Landscapes

• Combined Means For Separation Of Solids (AREA)
• Building Awnings And Sunshades (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=20405672

Family Applications (1)

Country Status (5)

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• 1997
  • 1997-02-04 SE SE9700385A patent/SE9700385L/ not_active IP Right Cessation
  • 1997-12-16 EP EP97950556A patent/EP0958067A1/de not_active Withdrawn
  • 1997-12-16 DE DE29780442U patent/DE29780442U1/de not_active Expired - Lifetime
  • 1997-12-16 WO PCT/SE1997/002105 patent/WO1998033604A1/en not_active Application Discontinuation
  • 1997-12-16 AU AU53529/98A patent/AU5352998A/en not_active Abandoned

Non-Patent Citations (1)

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