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(11) | EP 0 106 642 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Apparatus and method for fragmenting frangible objects |
| (57) Apparatus for fragmenting brittle or other breakable objects, such as scrap metal
castings or rock, includes a pivoted first crushing member (20, 50) and a fixed second
crushing member (14,54). The first member has a plurality of crushing regions (23,
24, 27) located at various distances from the pivot axis (26), which is offset, so
that each successive crushing region approaches the second member closer than the
preceding crushing region. The object is fragmented by a combination of compression
and shear forces. Projections (27) may be provided to localise the forces, and loose
members such as chains (56) may be utilised to dislodge adherent fragments from within
the apparatus. |
[0001] This invention relates to an apparatus and a method for fragmenting frangible objects, such as brittle scrap metal articles, or rocks. The invention is especially useful for crushing and fragmenting castings from motor vehicles, such as engine blocks with or without cylinder heads, and gearbox casings, and for giving quarried rock, for example chalk, a preliminary size reduction prior to finer comminution in a suitable mill.
[0002] In reclaiming materials from scrap motor vehicles, considerable high quality iron, steel and aluminium alloy can be recovered. In the case of engine castings in particular, the weight of the article can give rise to handling difficulties. Furthermore, in cases where high quality iron is to be recovered from the scrap, it is necessary to separate all steel, aluminium and copper, amongst other materials, from scrap iron before it is melted down. To accomplish either or both these ends it is desirable to break up brittle metal castings and thereby facilitate manual handling and the removal of unwanted metals and alloys.
[0003] In the processing of rock, such as chalk, which is to be powdered, it is convenient to be able to reduce the size of the larger pieces in the quarry so that the rock can be shipped onwards for further treatment as a fairly uniformly sized rubble.
[0004] It is an object of the invention to provide means for simply and efficiently fragmenting such objects in equipment that need not be costly to purchase, is simple to install wherever it is needed and can be economical in use.
[0005] In accordance with the present invention there is provided apparatus for fragmenting frangible objects, comprising first and second crushing members, the first crushing member being pivotally mounted with respect to the second crushing member, the first crushing member having a plurality of crushing regions for co-operating with the second crushing member to crush and fragment a said object therebetween, the said plurality of crushing regions being located at a variety of distances from the pivot axis and the pivot axis being so located with respect to the said crushing members that, on pivoting the first member with respect to the second member to crush a said object, a first crushing region of the first member approaches the second member to a closest distance which is not reduced on continuing the pivotal movement, and a second crushing region, following said first region, approaches the second member to a closer distance than the said closest distance reached by the first crushing region.
[0006] There is also provided a method of fragmenting a frangible object between a first crushing member pivotally mounted with respect to a second crushing member, wherein the first crushing member has a plurality of crushing regions for co-operating with the second crushing member to crush the object therebetween, and the said plurality of crushing regions are located at a variety of distances from the pivot axis; which method comprises pivoting the first member with respect to the second member about the pivot axis so located that a first crushing region of the first member approaches the second member to a closest distance which is not reduced on continuing the pivotal movement, and a second crushing region, following said first region, approaches the second member to a closer distance than the said closest distance reached by the first crushing region, the object being fragmented between the first crushing region and the second member and between the second crushing region and the second member.
[0007] By means of the invention, the frangible object is crushed and fragmented by regions of the first member which approach successively closer to the second member, thereby breaking up the object progressively. Since the relative movement between the two crushing members is centred on an offset pivot axis, in order to achieve the required movements of the first and second crushing regions of the first crushing member, there is also a shear effect to complement the compression between the crushing members. Every crushing region of the first member that approaches the second member to a closest distance that is not reduced by further movement, passes the nearest surface on the second member, as the pivotal movement continues, in a direction that is instantaneously parallel to that surface. In most cases there is also a substantial component of this shear action that is effective on either side of the closest approach of the crushing region to the second crushing member. -The combination of direct compression with transverse forces 1-s of considerable benefit in effectively and rapidly fragmenting a wide range of brittle or otherwise breakable objects.
[0008] In a preferred embodiment of the invention the first region of the first crushing member, and the second crushing member, define between them a throat through which fragments of the object can be discharged. The greatest opening of the throat, in the fully opened apparatus, defines the maximum size of fragment that can pass through. The greatest mechanical advantages obtain in those regions of the first crushing member that define the throat, allowing the greatest forces to be achieved in the throat, to deal with possible obstructions therein.
[0009] The apparatus is preferably so arranged that when it is open, which is to say when the first and second crushing members are pivoted apart from one another, the said members form entry guides, whereby to direct an object placed in the apparatus and to funnel fragments thereof towards the throat by means of gravity. Suitably, one crushing member is inclined and the other crushing member is either inclined or vertical. The crushing members may be provided with projections thereon, to localise the forces and thereby increase the local pressure applied to the object. Preferably fixed projections are provided on one only of the two crushing members, the other being without substantial obstruction to the passage of the object and fragments thereof. Loose, movable members may also or alternatively be provided between the first and second crushing members, such as chains slung slackly between the said crushing members, to help dislodge fragmented material, such as soft rock, that may adhere to the crushing members.
[0010] The pivotal relative movement between the two crushing members is preferably an oscillatory movement, in which partial closure to cause crushing and fragmentation is followed cyclically by opening to allow the now smaller pieces to fall further into the apparatus. The power for the movement may be taken from any suitable source: a hydraulic piston and cylinder assembly is usually preferred, but a pneumatic or mechanical drive for example may be used in appropriate cases.
[0011] The invention is illustrated by way of example in the accompanying drawings, in which:-
Figure 1 is side elevation of apparatus for fragmenting cast iron motor vehicle engine blocks and the like, the near side wall and longitudinal beam being shown cut away for clarity, the apparatus being shown open and ready to receive an engine block;
Figure 2 is a similar view of the apparatus partially closed on a partially fragmented engine block;
Figure 3 is a detail showing part of a crushing member textured with hard facing deposits;
Figure 4 is a view similar to Figure 1 of apparatus for fragmenting chalk; and
Figure 5 is a similar view of the apparatus of Figure 4 partially closed.
[0012] The apparatus as shown in Figs. 1 and 2 comprises a welded steel structure including two parallel, spaced apart, longi- . tudinal beams 11 (the nearer of which being cut away) joined at one end by two cross beams 12, 13 and near the other end by a flat plate 14 forming an end wall perpendicular to the longitudinal beams. Each longitudinal beam carries a vertical side wall 15 (the nearer of which is again shown cut away) extending from the plate 14 back towards the cross beams. The structure is braced behind the end wall 14 by two horizontal plates 16, 17 welded to the plate 14, to the ends of the side walls 15 and, in the case of the lower plate 17, to the tops of the beams 11. The plate 14 constitutes the second crushing member of the apparatus.
[0013] The first crushing member is constituted by the forward part of a welded steel box structure 20 which is pivotally mounted on a pivot axis 21 between the two longitudinal beams 11. The box structure comprises a pair of opposite side plates 22 lying close to the respective longitudinal beams 11 and side walls 15, spanned by three contiguous flat rectangular plates 23, 24 and 25 facing generally in the direction of the second crushing member and end wall plate 14, but each being angled differently thereto. Pivot bearings 26 in the side plates 22 are engaged by pins (not shown) carried on the beams 11.
[0014] Of the three rectangular plates 23, 24 and 25, the lowest plate 25 is provided primarily for strengthening purposes at the bottom of the box structure 20 and does not normally exert any significant crushing action. The intermediate plate 24 carries - two profiled steel bars 27a and -27b welded horizontally across its outer face. The uppermost and largest plate 23 similarly carries four such bars 27c, 27d, 27e and 27f at spaced intervals across its face. Each of the bars 27 is profiled to have a leading edge, as indicated at 29 on the bar 27a (Fig. 1). The plates 23 and 24 and the bars 27 together form a composite first crushing member.
[0015] A pair of cylinder mounting plates 31 on the cross beams 12, 13 carry the cylinder of a hydraulic ram 32, while the piston rod thereof is connected to the rear of the box structure 20, so that the ram can be used to drive the first crushing member towards the second crushing member.
[0016] For convenience, a conveyor belt 34 driven over supporting rollers 35 is located below the apparatus.
[0017] A motor vehicle engine block 36 can be lowered into the open apparatus by means of a hoist 37 (Fig. 1). At this stage the piston-and-cylinder assembly 32 is fully contracted and the first crushing member (the plates 23 and 24 and the bars 27) is fully withdrawn from the second crushing member (the end plate 14). The apparatus is mounted on or in a suitable support structure (not shown) so that the end plate 14 is inclined at an angle of from 0 to 45° from the vertical, in this case about 250. The uppermost plate 23 of the pivoted box structure 20 is also inclined from the vertical, in the opposite direction, so that the plates 14 and 23 define between them a narrowing guide passage which the engine 36 descends until it lodges between the two plates.
[0018] The engine 36 is to be fragmented by crushing between the first crushing member, namely the plates 23 and 24 and the bars 27 welded across them, and the second crushing member, namely the end wall plate 14. The plates 23, 24 and 14 and the bars 27 are of steel which is at least 25mm. in thickness, preferably about 50mm. thick, and the steel is preferably either wear resistant steel or mild steel that has been hard faced with a wear resistant deposit on the crushing surfaces of the components.
[0019] The ram 32 is extended to crush the engine block 36 as much as it can be crushed in a single stroke. It is then contracted, which re-opens the apparatus and allows the engine which is now reduced in size to fall further towards the narrowest part of the passage between the crushing members. Repeated cycles bring the plate 24 into use as well as the plate 23, and in due course fragments 39 of the engine fall through the apparatus on to the conveyor belt 34 (Fig. 2).
[0020] The conveyor carries the fragments away to be sorted, for example by the removal of brass fastenings, steel components including camshafts and crankshafts, and aluminium alloy components, from the cast iron, which can then be remelted for foundry use. The fragments are small enough to be readily handled manually.
[0021] In the embodiment of the invention illustrated in Figs. 1 and 2, the second crushing member 14 is fixed in the apparatus and the first crushing member is pivoted relative thereto on the pivot axis 26 which is offset from the planes of the principal working surfaces (plates 23, 24 and 14) of the first and second crushing members. The working surfaces of plates 23 and 24 on the pivoted box structure 20 lie between the pivot axis and the working surface of the fixed plate 14. This ensures that an article compressed between the first and second crushing members is also subjected to shear, or lateral, forces.
[0022] Different regions of the first crushing member are at different distances from the pivot axis. The regions defined by each of the bars 27, or more specifically by their leading edges 29, are successively more distant from the pivot axis from bar 27a through to bar 27f. Similarly there are regions of the plates 24 and 23 lying between the bars 27 which are successively more distant from the pivot axis. The leading edge of the bar 27a constitutes a first region of the first crushing member which, as the apparatus is closed, reaches a closest distance from the plate 14 and then starts to recede therefrom (Fig. 2). Further closing movement (assuming no article present to prevent such movement) brings a second region of the first crushing member, constituted by the leading edge of the bar 27b, closer to the plate 14 than the closest distance reached by the bar 27a. It is of interest that in relation to the bar 27c, which subsequently approaches plate 14 closer than the bar 27b, the bar 27b can also be considered a first crushing region and the bar 27c a second crushing region of the first crushing member.
[0023] The narrowest part of the passage through the open apparatus is the throat defined between the bar 28a and the plate 14. This throat establishes the largest size of fragment that can be passed through the apparatus, and it is in this region of the apparatus that the greatest- forces can be exerted on the article being crushed. The .narrowest gap in the throat is typically in the region of 10mm. to 150mm., and is preferably about 20mm. to 80mm., depending on the material to be fragmented and the desired fragment size range.
[0024] Narrowing the crushing regions of the bars 27 to a leading edge localises the forces and thereby increases the pressures that can be applied to the article. Preferably the leading edge is, in cross section, either a right angle or an acute angle, as illustrated, to aid biting into the article and to resist any tendency for the article to be squeezed upwardly out of the apparatus. While horizontal bars or other substantial projections on both the first and second crushing members would improve the grip on the article, they would also tend to hold up the article when the apparatus was re-opened after a previous compression. A crushing member without substantial projections may however suitably be textured to improve grip on the article without tending to hold it back on opening the apparatus. Suitable texturing may be provided by beads of a hard facing deposit which may be laid on the surface of the crushing member.
[0025] Fig. 3 shows an alternative version of the plate 23 and the bars 27. In this instance rectangular section steel bars 27' are welded horizontally across the face of a mild steel plate 23', the plate surface between the bars carries beads of a wear resistant hard facing deposit 42 in a criss-cross pattern and the bars carry beads of hard facing deposit in zig-zag patterns 43. In addition, the upper and lower forward edges of the bars carry heavy deposits 44 of hard facing metal.
[0026] The apparatus shown in Figs. 4 and 5 is essentially similar to that shown in Figs. 1 and 2, except in the following respects. The end wall plate 54 which constitutes the second crushing member is angled backwardly away from the first crushing member 50 so that it is inclined at about 7° to the vertical when the longitudinal beams 51 are horizontal. The first crushing member 50 is not provided with any additional bars corresponding to bars 27 on its front face, although it may be provided with a hard facing deposit, as may plate 54. Finally, steel chains 56 are slung loosely between the top edges of the first and second crushing members at intervals across the apparatus.
[0027] This embodiment of the apparatus is adapted for crushing and fragmenting chalk. The chains form projections lying against the faces of the respective crushing members to increase local pressures on the chalk rock when the apparatus is closed (Fig. 5), but more importantly help to dislodge adherent chalk when the apparatus is opened, pulling the chains away from the faces of the crushing members (Fig. 4).
[0028] In each embodiment of the apparatus, the several regions of the first crushing member describe rotary motions with respect to the fixed parts of the apparatus, including the second crushing member. Each such region moves in a circular arc about the pivot axis which is behind it, relative to the second crushing member. The successive first and second regions move in successively larger radii, each approaching the fixed crushing member, moving instantaneously parallel to it and then receding therefrom, as the pivoted first crushing member is advanced towards the second member, thereby to achieve efficient fragmenting of a frangible object in the course of several cycles of operation in which the apparatus is more nearly closed in each successive cycle.
1. Apparatus for fragmenting frangible objects, comprising first and second crushing
members, the first crushing member being pivotally mounted with respect to the second
crushing member, characterised in that the first crushing member (20, 50) has a plurality
of crushing regions (24, 23; 27) for co-operating with the second crushing member
(14, 54) to crush and fragment a said object (36) therebetween, the said plurality
of crushing regions being located at a variety of distances from the pivot axis (26)
and the pivot axis being so located with respect to the said crushing members that,
on pivoting the first member with respect to the second member to crush a said object,
a first crushing region (24; 27a) of the first member approaches the second member
to a closest distance which is not reduced on continuing the pivotal movement, and
a second crushing region (23; 27b, c, d, e) following said first region, approaches
the second member to a closer distance than the said closest distance reached by the
first crushing region.
2. Apparatus according to claim 1 wherein the first region (27a) of the first crushing
member (20), and the second crushing member (14), define between them a throat through
which fragments of the object can be discharged.
3. Apparatus according to claim 2 wherein the throat has a narrowest gap of 10 - 150
mm, and preferably of 20 - 80 mm.
4. Apparatus according to claim 2 or claim 3 wherein the first and second crushing
members (20, 14; 50, 54) form entry guides when pivoted apart from one another whereby
to direct an object (36) placed in the apparatus and to funnel fragments thereof towards
the throat by means of gravity.
5. Apparatus according to any one of the preceding claims wherein the second crushing
member (14) is fixed and inclined at an angle of not more than 45° to the vertical.
6. Apparatus according to any one of the preceding claims wherein one only or both
of the first and second crushing members (20, 14; 50, 54) are provided with projections
(27) thereon to increase the local pressure applied to the object.
7. Apparatus according to any one of the preceding claims wherein loose, movable members
(56) are provided between the first and second crushing members (50, 54) to dislodge
fragmented material that may adhere to the crushing members.
8. Apparatus according to any one of the preceding clqims wherein at least one of
the first and second crushing members (20, 14; 50, 54) is provided with a textured
and/or wear resistant hard faced working surface.
9. Apparatus according to any one of the preceding claims wherein the first and second
crushing members (23, 24, 27, 14) are of steel at least 25 mm thick.
10. A method of fragmenting a frangible object between a first crushing member pivotally
mounted with respect to a second crushing member, characterised in that the first
crushing member (20, 50) has a plurality of crushing regions (24, 23; 27) for co-operating
with the second crushing member (14, 54) to crush the object (36) therebetween, and
the said plurality of crushing regions are located at a variety of distances from
the pivot axis (26); which method comprises pivoting the first member with respect
to the second member about the pivot axis so located that a first crushing region
(24; 27a) of the first member approaches the second member to a closest distance which
is not reduced on continuing the pivotal movement, and a second crushing region (23;
27b, c, d, e), following said first region, approaches the second member to a closer
distance than the said closest distance reached by the first crushing region, the
object being fragmented between the first crushing region and the second member and
between the second crushing region and the second member.
11. A method according to claim 10 wherein the first member is pivoted with respect
to the second member in an oscillatory movement.
12. A method according to claim 10 or claim 11 wherein the object (36) is a scrap
metal article.
13. A method according to claim 10 or claim 11 wherein the object is rock.