GB2352412A

GB2352412A - Rotary shear and components

Info

Publication number: GB2352412A
Application number: GB0017945A
Authority: GB
Inventors: Alan Rodney Pickard; Lyndon Nicholas Pickard
Original assignee: Powertech Industrial Co Ltd
Current assignee: Powertech Industrial Co Ltd
Priority date: 1999-07-24
Filing date: 2000-07-24
Publication date: 2001-01-31
Also published as: GB9917362D0; GB0017945D0

Abstract

A system for releasably latching a pick (12) or blade to a supporting segment (1, 1B) for fitting to a ring (2, 2A) of a rotary shear or shedder, comprises a segment (1, 1B) with an arcuate base (4) to seat on a portion (37) of an arcuate external periphery of the ring (2, 2A) with male-to-female engagement between the segment (1, 1B) and the ring (2, 2A); a rectangular aperture (10) in the segment (1, 1B) to receive a rectangular shank (11) of a replaceable pick (12) or blade having an enlarged head (12) exterior to the aperture (10) and provided with two working faces (14, 15) or edges 180{ apart; a latching recess (18) on two opposed faces of the shank (11) with one recess aligned with apertures (16) in side cheeks of the segment (1, 1B) whereby a resilient knock-in, knock-out latching device (19) retains the pick shank (11) within its aperture (10); a mouth (36) of the aperture (10) being provided with four outwardly tapered surfaces (37), and a transition portion (38) between the enlarged head (13) and the shank (11) being provided with four corresponding chamfers (39) to seat on the tapered surfaces (37), to ensure self-centring of the shank (11) within its aperture (10); and a seating surface (40) of the enlarged head (13) engaging an abutment surface (43) of the segment (1, 1B). The segment is secured to the ring by means of a T-headed bolt (39).

Description

T 2352412

Title of the Invention

Rotary shear and components Field of the Invention

This invention relates to various components of a rotary shear or shredder for use in conjunction with either a static anvil or a second rotary shear or shredder, for the crushing or sizing of materials (eg minerals, rock, coal, aggregates, slag), or for the shredding of (eg scrap metal, scrap motor vehicles, domestic refuse), to a handlable and reasonably uniform size, and specifically to a system for releasably latching a pick or blade to a supporting segment.

Background of the Invention

One rotary shear or shredder is described in our co-pending patent application published as GB 23223 10, and another in US 4125228. The latter has teeth spaced 180' apart and shreds against a static anvil. Both constructions require a plurality of tapped radial holes in a ring to receive bolts serving to secure segments to the ring, with a plurality of rings arranged side by side on a common drive shaft. Invariably, the teeth become wom or damaged, requiring replacement. Production of tapped radial holes incurs machining costs, whilst the removal of damaged, bent or rusted-in bolts sometimes incurs delays, whilst pick or blade securing also involves a screwed construction. In all, several hours are required for a total segment and/or pick/blade replacement.

Object of the Present Invention A basic object of the present invention is the provision of improved components of a rotary shear or shredder.

2 Summary of the First Aspect of the Invention

According to a first aspect of the invention, there is provided a system for releasably latching a pick or blade to a supporting segment for fitting to a ring of a rotary shear or shredder, comprising:

(i) a segment with an arcuate base to seat on a portion of an arcuate external periphery of the ring with male-to-female engagement between the segment and the ring; (ii) a rectangular aperture in the segment to receive a rectangular shank of a replaceable pick or blade having an enlarged head exterior to the aperture and provided with two working faces or edges 180' apart; (iii) a latching recess on two opposed faces of the shank with one recess aligned with apertures in side cheeks of the segment whereby a resilient knock-in, knock-out latching device retains the pick shank within its aperture; (iv) a mouth of the aperture being provided with four outwardly tapered surfaces, and a transition portion between the enlarged head and the shank being provided with four corresponding chanifers to seat on the tapered surfaces, to ensure self- centring of the shank within its aperture; and (v) a seating surface of the enlarged head engaging an abutment surface of the segment.

The segment in accordance with the first aspect of the invention provides for the use of a double life pick that is readily reversible when the first blade or face is damaged, simply by knocking out the latching device, withdrawing the pick shank, rotating it through 180', replacing the pick shank, and knocking the latching device back into its retaining position, providing a substantial simplification, and attendant rapidity, in pick replacement time.

3 Preferred Features are as follows:

The shank is rectangular.

The latching recess is a groove in opposed faces of the shank.

The latching device comprises a composite element comprising a central, resilient rubber compound bonded to opposed steel side faces each with a narrowed, lead-in nose.

The aperture and shank are so dimensioned that the shank may be readily fitted, and removed, by hand.

The aperture is blind, but may have a bore co-axial with the aperture, to receive a drift or chisel, whereby a "stuck7' shank may be hammered from the aperture.

The segment has a single, male projection.

The projection has opposed faces on a 15' taper.

The segment has a radial hole to receive a threaded shank of a securing bolt, the hole terminating at an enlarged recess to house a securing nut for the threaded shank.

The segment has two radial holes spaced eg 60' apart, to receive the shanks of two securing bolts.

In another embodiment the segment has an angled forward face and an angled rearward face for engagement by clamping wedges.

The segment has a pair of axially spaced-apart side cheeks, each with an arcuate surface to engage a corresponding surface of the ring to which the segment is fitted, in use.

The cheeks subtend, in first embodiment, an angle of 60', and in second embodiment, an angle of 120'.

Thus with segments in accordance with the first embodiment, six are required and in accordance with the second embodiment three are required.

It will be appreciated that infill segments without provision for mounting a cutter pick 4 may be provided, so that, with 60' segments, up to five infill segments could be provided, and with the 120' segments, up to two infill segments could be provided. The choice depends on several factors, not least the nature of the material to be sheared or shredded.

Summary of the Second Aspect of the Invention

According to a second aspect of the invention, of independent significance, there is provided a securing system for securing a component, such as a segment or clamping wedge, to the periphery of a ring of a rotary shear or shredder with a male/female engagement between the component and ring, comprising:

(i) a plurality of 'T'-bolts, with the head of each bolt fitted into an enlarged portion of a 'T'- slot in the ring leading to a narrowed throat portion of the 'T' slot to receive an externally or intemally threaded stem of the bolt; (ii) a plain, radial bore in the component to accommodate, with clearance the bolt stem; and (iii) the radial outer end of the bore terminating in an enlarged recess incorporating a transverse tightening surface to house a cooperating screw member to secure the component to the ring.

With respect of the invention, the need for finish machining and then tapping of < 12 radial holes in the rotor is eliminated, as broad tolerances may be accepted between the 'T'-slot in the rotor and the 'T-bolts, such that the 'T'-slots may be produced to sufficient accuracy during casting, thereby substantially reducing production costs.

Preferred Feature of the Second Aspect of the Invention The co-operating screw member is a nut to screw on to an externally threaded bolt stem.

The co-operating screw member is a stud, to screw into an internally threaded bolt stem.

In one embodiment, the component is a segment extending over 120 ', with two radial bores at 60' to receive the stems of two 'T'-bolts.

In another embodiment, the component is a clamping wedge with one radial bore to receive the stem of a 'T'-bolt, the wedge providing a transverse tightening surface for engagement by the screw member, opposed, mutually tapering clamping surfaces, and a male-to female inter-engagement between the wedge and the ring, so that the opposed, tapering, clamping surfaces may engage adjacent surfaces of adjacent segments, whereby generally tangential loads on the picks are transmitted from segment to segment and from the segments to the rotor, so that the 'T'-bolts are subjected only to tensile loading.

A terminal end of each narrow throat portion is flared, to define a generally 'V'-recess, with two complementary 'V'-proj ections on each 120' segment to engage the recesses, again for primary load transfer purposes.

The head of each 'T'-bolt has non-radial, but inclined, abutment surfaces, for engaging complementary surfaces of the enlarged portion of the 'T'-slot.

With the screw member constituted by a nut the latter is provided with an integral locking ring eg of nylon or other synthetic plastic.

The transverse tightening surface is tangential to the rotor axis.

fhe male-to-female engagement comprises a single male projection on the clamping peg.

The projection is tapered.

The recess housing the screw member is closed off by a push-in, prise-out bung.

The bung is of abrasion resistant material eg polyurethane.

The ring is provided with six 'T'-slots spaced 60' apart.

The ring has a circumferential periphery comprising a pair of axially spaced seating 6 shoulders separated by a central rib.

The rib has a castellated profile comprising a plurality eg twelve, equally spaced male projections, with eg twelve female recessed defined between adjacent projections.

Each segment is provided with side cheeks to fit, saddle-like, over the rib.

Brief Description of the Drawings

Examples of the various aspects of the invention are shown in the accompanying drawings, in which:

Figures I and 2 are respectively a side elevation and an end elevation of a segment, to support a replaceable pick or blade in accordance with the first aspect of the invention, with the pick removed; Figures 3 and 4 are respectively a side elevation and an end elevation of a ring showing both the securing system of the second aspect of the invention and the segment of the first aspect of the invention fitted with a pick; Figures 5 and 6 correspond to Figures 3 and 4 but show only the ring, partly in section; Figures 7 and 8 are respectively a side elevation and a transverse sectional view through a leading clamping peg (in the direction of ring rotation); Figures 9 and 10 correspond to Figures 7 and 8 but show a trailing clamping peg; Figures I I and 12 correspond to Figures I and 2 but show an infill segment for fitting at a location where no pick is required; Figures 13 and 14 are respectively a side elevation and a transverse sectional view through another form of clamping wedge for use between segments of Figures I I and 12; Figure 15 corresponds to Figure 3, but shows a second embodiment in which three 120' segments are fitted to a ring; 7 Figure 16 is a sectional view through the ring of Figure 15; and Figure 17 is an end elevation of the ring of Figure 15.

In both embodiments, like components are accorded a like reference numeral.

In Figures I and 2, a segment 1, subtending an arc of 60' is intended, as indicated in Figure 3, to be mounted on a ring 2 having a hexagonal aperture 3 for mounting on a hexagonal drive shaft (not shown) of a shredder.

Each segment I comprises an arcuate base 4 and a pair of spaced side cheeks 5 also having an arcuate profile 6.

The base 4 is adapted to seat on arcuate surfaces 7 of the castellated periphery of the ring 2, the segment I having a male projection 8, tapered at 15', to fit a corresponding female recess 9 of the ring 2.

The segment I has a rectangular aperture 10 to receive a rectangular shank I I of a replaceable pick 12 having an enlarged head 13 provided with two working faces 14, 15 which are 180' apart. Intersecting the aperture 10 are rectangular apertures 16, whilst the pick 12 has recesses 17, 18 in opposed faces so that, when a pick is inserted into the aperture 10, a knock-in, knock-out latching device 19, eg of resilient plastics, passes through one aligned recess 17 or 18, and the aperture 16, to releasably latch the pick 12 to the segment I to the ring 2. A mouth 38 of the aperture 10 is provided with four outwardly tapered surfaces 3 9, whil st a transition portion of the pick 12 between its shank I I and its enlarged head 13 is provided with four corresponding chanifers 41 to seat on the surfaces 39 when a seating surface 42 of the enlarged head 13 engages abutment surface 43 at the mouth 38.

Figure 3 indicates a ring 2 with but one 60' segment 1, although six such segments 1 could be fitted, if required.

Figure 3 indicates the fill, of fine infill segments I A, as detailed in Figures I I and 12.

Between the segment I and IA is interposed a leading clamping wedge 19 detailed in Figures 7 and 8, and a trailing clamping wedge 2 1, detailed in Figures 9 and 10.

Between each 60' infill segment 2A is a third form of intermediate clamping wedge 22, detailed in Figures 13 and 14.

As best seen in Figures 3 to 6, the ring 2 is provided with six 'T'-slots 23 at 60' spacing.

Each 'T'-slot 23 has an enlarged portion 24 leading to a narrowed throat portion 25.

A plain bore 26 passes through each leading clamping wedge 2 1, and intermediate wedge 22, leading to an enlarged recess 27 incorporating a transverse tightening surface 28.

A 'T'-bolt 29 is fitted into each slot 23, comprising an enlarged head 3 0 and an integral stem 3 1.

In the embodiment of Figures 3 and 4, the stem 31 is externally threaded, is of length to pass into an enlarged recess 27, where a nut 32 is applied, and tightened.

As best seen in Figures 4 to 6, the ring has a circular periphery comprising a pair of axially spaced seating shoulders 36 separated by a central, castellated rib portion 37, which shoulders and rib are engaged by the surfaces 6 and 8 respectively of each segment 1, IA.

In the embodiment of Figures 15 to 17, three 120 ' segments 1 B are secured by two 'T' bolts each, these 'T'-bolts 29A being internally threaded, so that a hexagonal headed stud 32A may be applied, and tightened.

Also as shown in Figure 15, is that each segment I B, has a pair of 'V'shaped engagement ribs 33 spaced 60' apart and to each side of the male projection 8, to engage 'V'-shaped recesses 34 in the ring 2A. An aperture 35 in the segment I B enables a drift to be knocked in, to dislodge a stuck pick 12, while aperture 3A in the ring 2A is provided for a keyed location on a drive shaft.

Although Figure 15 shows the attachment of three segments I B, each carrying a pick, it 9 is of course possible, as discussed with regard to Figure 3, to employ but one such segment I B, with two "infill" segments without apertures for picks, in the same manner as segment I A of Figure 3, to meet specific shearing or shredding requirements, as balance is not a problem because rotation is normally only 8 - I I r.p.m.

Claims

I A system for releasably latching a pick or blade to a supporting segment for fitting to a ring of a rotary shear or shredder, comprising a segment with an arcuate base to seat on a portion of an arcuate external periphery of the ring with male-to- female engagement between the segment and the ring; a rectangular aperture in the segment to receive a rectangular shank of a replaceable pick or blade having an enlarged head exterior to the aperture and provided with two working faces or edges 180' apart; a latching recess on two opposed faces of the shank with one recess aligned with apertures in side cheeks of the segment whereby a resilient knock-in, knock-out latching device retains the pick shank within its aperture; a mouth of the aperture being provided with four outwardly tapered surfaces, and a transition portion between the enlarged head and the shank being provided with four corresponding charnfers to seat on the tapered surfaces, to ensure self centring of the shank within its aperture; and a seating surface of the enlarged head engaging an abutment surface of the segment.
2. A system as claimed in Claim 1, wherein the latching recess is a groove in opposed faces of the shank.
3. A system as claimed in any preceding Claim, wherein the latching device comprises a composite element comprising a central, resilient rubber compound bonded to opposed steel side faces each with a narrowed, lead-in nose.
4. A system as claimed in any preceding Claim, wherein the segment has a single, male projection.

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5. A system as claimed in any preceding Claim, wherein the projection has opposed faces on a 15 ' taper.
6. A system as claimed in any preceding Claim, wherein the segment has a radial hole to receive a threaded shank of a securing bolt, the hole terminating at an enlarged recess to house a securing nut for the threaded shank.
7. A system as claimed in any preceding Claim, wherein the segment has two radial holes spaced eg 60' apart, to receive the shanks of two securing bolts.
8. A system as claimed in any one of Claims I to 6, wherein the segment has an angled forward face and an angled rearward face for engagement by forward and rearward clamping wedges.
9. A system as claimed in any preceding Claim, wherein the segment has a pair of axially spaced-apart side cheeks, each with an arcuate surface to engage a corresponding surface of the ring to which the segment is fitted, in use.
10. A system as claimed in any preceding Claim, wherein the segments subtend an angle of 600.
11. A system as claimed in any one of Claims I to 10, wherein the segments subtend an angle of 120'.
12 12. A securing system for securing a component, such as a segment or clamping wedge, to the periphery of a ring of a rotary shear or shredder with a male/female engagement between the component and ring, comprising a plurality of 'T'-bolts, with the head of each bolt fitted into an enlarged portion of a 'T'- slot in the ring leading to a narrowed throat portion of the 'T' slot to receive an externally or intemally threaded stem of the bolt; a plain, radial bore in the component to accommodate, with clearance the bolt stem; and the radial outer end of the bore terminating in an enlarged recess incorporating a transverse tightening surface to house a cooperating screw member to secure the component to the ring.
13. A system as claimed in Claim 12, wherein the co-operating screw member is a nut to screw on to an externally threaded bolt stem.
14. A system as claimed in Claim 12, wherein the co-operating screw member is a stud, to screw into an internally threaded bolt stem.
15. A system as claimed in any preceding Claim, wherein the component is a segment extending over 120', with two radial bores at 60' to receive the stems of two 'T'-bolts.
16. A system as claimed in any one of Claims 13 to 15, wherein the component is a clamping wedge with one radial bore to receive the stem of a 'T'-bolt, the wedge providing a transverse tightening surface for engagement by the screw member, opposed, mutually tapering clamping surfaces, and a male-to-female inter-engagement between the wedge and the ring.

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17. A system as claimed in Claim 16, wherein a terminal end of each narrowed throat portion is flared, to define a generally 'V'-recess, with two complementary 'V'- projections on each 120' segment to engage the recesses.
18.A system as claimed in any preceding Claim, wherein the head of each 'T'-bolt has non- radial, but inclined, abutment surfaces, for engaging complementary surfaces of the enlarged portion of the 'T'-slot.
19. A system as claimed in any one of Claims 12 to 18, wherein, with the screw member constituted by a nut, the latter is provided with an integral locking ring eg of nylon or other synthetic plastic.
20. A system as claimed in any one of Claims 12 to 22, wherein the transverse tightening surface is tangential to an axis of rotation of the ring.
21. A system as claimed in any one of Claims 12 to 23, wherein the maleto-female engagement comprises a single male projection on the clamping peg
22. A system as claimed in Claim 21, wherein the projection is tapered.
23. A system as claimed in any one of Claims 12 to 22, wherein the recess housing the screw member is closed off by a push-in, prise-out bung.
24. A system as claimed in Claim 23, wherein the bung is of abrasion resistant material eg 14 polyurethane.
25. A system as claimed in any of Claims 12 to 24, wherein the ring is provided with six T'-slots spaced 60' apart.
26. A system as claimed in any one of Claims 12 to 25, wherein the rotor has a circumferential periphery comprising a pair of axially spaced seating shoulders separated by a central rib.
27. A system as claimed in Claim 26, wherein the central rib has a castellated profile comprising a plurality eg twelve, equally spaced male projections, with eg twelve female recessed defined between adjacent projections.
28. A system as claimed in Claim 27, wherein each segment is provided with side cheeks to fit, saddle-like, over the central rib.
29. A system for releasably latching a pick or blade to a supporting segment for fitting to a ring, substantially as herein before described in Figures I to 14 of the accompanying drawings.
30. A system for releasably latching a pick or blade to a supporting segment for fitting to a ring, substantially as herein before described in Figures 15 to 17 of the accompanying drawings.
31. A securing system for securing a component, such as a segment or clamping wedge, to the periphery of a ring, substantially as herein before described in Figures I to 14 of the accompanying drawings.
32.A securing system for securing a component, such as a segment or clamping wedge, to the periphery of a ring, substantially as herein before described in Figures 15 to 17 of the accompanying drawings.
33. A rotary shear or shredder incorporating a system for releasably latching a pick or blade to a supporting segment for fitting to a ring, the system being as defined in any one of Claims I to 11, 29 or 30.
34. A rotary shear or shredder for securing a component, such as a segment or a clamping wedge, to the periphery of a ring, the system being as defined in any one of Claims 12 to 28, 31 or 32.