BASKET-FRAME UNIT FOR CONTINUOUS ENDLESS-CONVEYOR RIDDLE

Abstract: The unit is suitable to riddle, transport and discharge material continuously, the material being taken advantageously from railway road beds in rehabilitation work on such beds, the unit comprising an outer riddle surface (11) retaining material of too great piece size and an inner riddle surface (12) retaining the rehabilitation material, the two riddle surfaces (11-12) being positioned parallel to each other, the basket-frame unit (10) cooperating with link elements (21), the outer and inner riddle surfaces (11-12) being contained between lateral plates (15) connected to the link elements (21) that form the chains which move the basket-frame unit (10) forwards, the lateral plates (15) having a mean length­ wise extent greater than the lengthwise extent of the outer and inner surfaces (11-12).

Description: This invention concerns a basket-frame unit for a continuous endless-conveyor riddle. To be more exact, the invention concerns a basket-frame unit suitable to riddle, transport and discharge continuously material taken from railway road beds in rehabilitation work on such beds. The basket-frame unit cooperates with a plurality of equal units which are positioned contiguous to each other so as to form beds to convey materials being riddled in the continuous riddle. The state of the art includes embodiments intended to riddle the metalling forming the road bed and to eliminate the too great materials (blocks and the like) and too small materials (earth, mud and clay) and to recycle the materials which are dimensionally most suitable. Such known embodiments provide for the metalling taken from the road bed to be transferred onto vibratory riddle means. The vibratory riddle means entail a plurality of shortcomings linked mainly to the self-unbalancing nature of the system during the course of the riddling operations, such self-unbalancing being progressively accentuated while the riddling efficiency continues decreasing. EP 0184236 (corresponding to the preamble of claim 1) discloses a double continuous riddle with links cooperating with an outer surface and an inner surface connected so as to form an endless conveyor belt. US 1,940,832 deals with a conveyor with elements connected to each other by rocking links but this teaching is very different from the contents of our present invention. FR 2.370.527 shows a system of connection of links of a conveyor by means of joints, but this system cannot be applied to our invention. US 2,594,991 shows a normal, suitably formed chain for excavation and conveying purposes. The present applicants have designed, tested and embodied a basket-frame unit which, when employed in a continuous riddle, overcomes the problems of the state of the art. The basket-frame unit according to the invention consists of two parallel riddle surfaces, one of them an outer surface and the other an inner surface, which are connected together by lateral walls. The outer riddle surface is suitable to retain materials of a too big piece size, whereas the inner surface is suitable to retain rehabilitation material. The too fine material passes through the two riddle surfaces and is discharged suitably. Link elements are fixed to the side walls of the basket-frame unit and together with suitable connection elements, form the links of a double endless chain which is actuated by suitable terminal pinions. When fitted to the double chain, two neighbouring basket-frame units provide a lengthwise overlapping segment of their respective lateral walls in the zone of horizontal or substantially horizontal movement of the riddle. Such overlapping of the lateral walls of two neighbouring basket-frame units forms a continuous side wall for lateral retention of the material being riddled. In the zone where the riddle slides substantially horizontally, the outer and inner riddle surfaces of two neighbouring basket-frame units are positioned reciprocally so as to form continuous riddle surfaces. At the bends where the riddle is wound on terminal pinions, the outer surface of each basket-frame unit is distanced from that of the unit following it in the direction of movement, whereas the inner surface maintains its continuity with the following inner surface. The reciprocal distancing of the outer riddle surfaces of neighbouring basket-frame units assists the exit of the rehabilitation materials in the zone of the discharge of materials. The invention is therefore embodied according to the content of Claim 1 and the dependent claims. The attached figures, which are given as a non-restrictive example, show the following:- Fig. 1 gives a front view of a basket-frame unit according to the invention; Fig. 2 is a side view of the basket-frame unit of Fig. 1; Fig. 3 is a partial view of the basket-frame unit of Fig. 1 in the direction A; Fig. 4 is a partial section of the basket-frame unit of Fig. 1 according to the line B-B; Fig. 5 is a link employed in the basket-frame unit of Fig. 1, shown in an enlarged scale as compared to the preceding figures; Fig. 6 is a side view of the link of Fig. 5; Fig. 7 is a connection element for links of Fig. 5. A basket-frame unit 10 according to the invention consists of an outer riddle surface 11 and inner riddle surface 12, such surfaces 11-12 being located on parallel planes. In the example shown the surfaces 11-12 consist of transverse rods 13 and lengthwise rods 14 fixed to each other to form a riddle mesh of required dimensions. The inner surface 12 has a density of transverse rods 13 and lengthwise rods 14 greater than the analogous density of the outer surface 11. The surfaces 11-12 can be embodied with elements other than rods 13-14, and many variants are possible without departing thereby from the scope of the invention. The transverse rods 13 of the riddle surfaces 11-12 are fixed terminally to lateral plates 15, which comprise a vertical tract 16 that extends above the outer surface 11, and a sloped tract 17 that is inclined towards the inside of the basket-frame unit 10. This sloped tract 17 is advantageous for the limitation of the overall transverse bulk of the basket-frame unit 10 and is positioned in correspondence with the greatest protrusion of a link of a chain, as will be described later. The riddle surfaces 11-12 are connected to each other by a plurality of stiffening ties 18 of a required number and shape. These ties 18 have the further task of retaining, in the direction of the forward movement of the basket-frame unit 10 and riddle, the rehabilitation material held on the inner riddle surface 12 without thereby hindering the discharge of the rehabilitation material in a radial direction. The lateral plates 15 comprise distancer blocks 19, which are the same as each other but are fixed in a differentiated manner to the plates 15, or else one of the distancer blocks 19 is positioned so as to protrude sideways from the volume of the basket-frame unit 10 by a required extent. The blocks 19 include holes 20 which cooperate with upper holes 120 in a link 21 so as to anchor that link 21 to its respective lateral block 19 with means of the state of the art. The upper holes 120 in the link 21 may be positioned closer to or farther from first 23 and second 24 holes in the lower part of the link in a direction normal to the line joining the axes of the first and second holes 23-24. If the upper holes 120 are displaced, the behaviour of the basket-frame unit 10, particularly at the bends of the winding of the unit, will vary so that it is possible to obtain a behaviour differentiated as desired both of the outer riddle surface 11 and of the inner riddle surface 12, such behaviour resulting in a greater or lesser continuity of the riddle surfaces 11-12. Each link 21 has in its lower part a structure 22 shaped as an overturned "U" with the first 23 and second 24 lengthwise holes. Within the U-shaped structure 22 is located a connecting element 25, in which a first hole 124 cooperates with the second hole 24 in the link 21 and is secured thereto with the ability to rotate, whereas a second hole 123 in the connecting element 25 will cooperate with the first hole 23 of the link 21 of the neighbouring basket-frame unit 10. The links 21 and connecting elements 25 form in this way on each side of the basket-frame units 10 a chain to draw the basket-frame units 10. The basket-frame units 10 are elements which connect the two lateral chains. The lateral position of the respective links 21 in relation to the basket-frame unit 10 is differentiated since one of the links 21 is positioned more outwards owing to the different anchorage of the distancer blocks 19 on the lateral plates 15. This enables the basket-frame units 10 to be positioned in the riddle one after another and rotated by 180° in relation to one another so as to obtain a partial lengthwise overlapping of the lateral plates 15 of neighbouring basket-frame units 10 on both sides of the basket-frame units 10. A required lateral barrier is produced in this way to retain the material being riddled in the substantially horizontal tracts of the movement of the riddle. The transverse 13 and lengthwise 14 rods of the outer 11 and inner 12 riddle surfaces are positioned reciprocally in such a way as to form continuous riddle surfaces, as shown with lines of dashes in Figs. 3 and 4, with the rotation of one basket-frame unit 10 by 180° in relation to the neighbouring basket-frame unit 10.

Claims: Basket-frame unit (10) for a continuous endless-conveyor riddle, the unit being arranged normal to the direction of movement of the riddle and being suitable to riddle, transport and discharge continuously material taken advantageously from railway roadbeds in work to rehabilitate such beds, the unit comprising an outer riddle surface (11) retaining material of too great a piece size and an inner riddle surface (12) retaining the rehabilitation material, the two surfaces (11-12) being positioned parallel to each other, the basket-frame unit (10) having link elements (21) for cooperation with adjacent units and being characterized in that the outer and inner riddle surfaces (11-12) are contained between two lateral plates (15) parallel to the direction of movement and connected to the link elements (21) that form the chains which draw the basket-frame unit (10), the lateral plates (15) having a mean lengthwise extent greater than the lengthwise extent of the outer and inner riddle surfaces (11-12), each of the lateral plates (15) comprising outer distancer blocks (19) containing holes (20) for fixture of the link elements (21). Basket-frame unit (10) as claimed in Claim 1, in which one distancer block (19) protrudes more than the other. Basket-frame unit (10) as claimed in Claim 1 or 2, in which the lateral plates (15) comprise a vertical tract (16) extending substantially higher than the outer riddle surface (11). Basket-frame unit (10) as claimed in any claim hereinbefore, in which the lateral plates (15) comprise an inwardly sloped tract (17) extending substantially between the outer riddle surface (11) and inner riddle surface (12). Basket-frame unit (10) as claimed in any claim hereinbefore, in which cross-brace connection means (18) to retain rehabilitation material are included between the inner riddle surface (12) and outer riddle surface (11). Basket-frame unit (10) as claimed in any claim hereinbefore, in which the link elements (21) comprise in their lower portion a structure shaped as an overturned "U" (22). Basket-frame unit (10) as claimed in any claim hereinbefore, in which each link element (21) is fitted to its own basket-frame unit (10) and cooperates with adjacent link elements (21) by means of reciprocal connecting elements (25). Basket-frame unit (10) as claimed in any claim hereinbefore, in which in the zones of substantially horizontal sliding of the riddle the adjacent outer riddle surface (11) and inner riddle surface (12) of the basket-frame units (10) are substantially in contact with each other so as to form a continuous riddle surface. Basket-frame unit (10) as claimed in any claim hereinbefore, in which the positioning of the upper holes (120) connecting the link elements (21) to the basket-frame units (10) in relation to the line joining the axes of the first (23) and second (24) lengthwise holes depends on the behaviour of the outer and/or inner riddle surfaces (11-12) at the curves of the winding of the surfaces.

Inventors: CICIN-SAIN, IVO
Applicants: DANIELI & C. OFFICINE MECCANICHE S.P.A., ITI/CLM IMPIANTI TECNICI INDUSTRIALI SPA
Application year: 1988
Main classification: E01B27
IPC codes: E01B27, B07B1