[0001] 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.
[0002] 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.
[0003] 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.
[0004] 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.
[0005] EP 0184236 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.
[0006] 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.
[0007] 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.
[0008] US 2,594,991 shows a normal, suitably formed chain for excavation and conveying purposes.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] The too fine material passes through the two riddle surfaces and is discharged suitably.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] The invention is therefore embodied according to the content of Claim 1 and the dependent
claims.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] The riddle surfaces 11-12 are connected to each other by a plurality of stiffening
ties 18 of a required number and shape.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] The basket-frame units 10 are elements which connect the two lateral chains.
[0036] 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.
[0037] 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.
[0038] 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.
[0039] 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.
1 - Basket-frame unit for a continuous endless-conveyor riddle, the unit being 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 surfaces
(11-12) being positioned parallel to each other, the basket-frame unit (10) cooperating
with link elements (21) and being characterized in that the outer and inner riddle
surfaces (11-12) are contained between lateral plates (15) connected to link elements
(21) that form the chains which move the basket-frame unit (10) forwards, the lateral
plates (15) having a mean lengthwise extent greater than the lengthwise extent of
the outer and inner riddle surfaces (11-12).
2 - Basket-frame unit as claimed in Claim 1, in which one of the link elements (21)
of the basket-frame unit (10) is fixed to its respective lateral block (19) in such
a way that it protrudes further laterally than the other link element (21) of the
same unit (10).
3 - Basket-frame unit as claimed in Claim 1 or 2, in which the lateral plates (15)
comprise a vertical tract (16) protruding substantially higher than the outer riddle
surface (11).
4 - Basket-frame unit as claimed in any claim hereinbefore, in which the lateral plates
(15) include a sloped tract (17) extending substantially between the outer riddle
surface (11) and inner riddle surface (12).
5 - Basket-frame unit as claimed in any claim hereinbefore, in which means (18) which
retain rehabilitation material are included between the outer (11) and inner (12 riddle
surfaces.
6 - Basket-frame unit as claimed in any claim hereinbefore, in which the links (21)
comprise a structure (22) shaped as an overturned "U" in their lower portion.
7 - Basket-frame unit as claimed in any claim hereinbefore, in which each link (21)
supports its own basket-frame unit (10) and cooperates with the links (21) of the
neighbouring basket-frame units (10) by means of reciprocal connecting elements (25).
8 - Basket-frame unit as claimed in any claim hereinbefore, in which in the zones
of substantially horizontal running of the riddle the outer (11) and inner (12) riddle
surfaces form continuous riddle surfaces together with the outer (11) and inner (12)
surfaces of the neighbouring basket-frame units (10).
9 - Basket-frame unit as claimed in any claim hereinbefore, in which upper holes (120)
which connect the links (21) to the basket-frame unit (10) are positioned as desired
in relation to the line joining the axes of first (23) and second (24) lengthwise
holes in the lower part of the link (21) so as to vary the behaviour of the outer
(11) and/or inner (12) riddle surfaces advantageously at the bends of the winding
of the riddle.