The present invention relates to a mantle lifting device for lifting a mantle from a cone crusher. The invention also relates to a method of lifting a mantle.
A typical cone crusher comprises an offset cone head which gyrates about a central axis. To protect the cone head from wear, a mantle is attached to and overlies the cone head. During operation as the cone head gyrates about the central axis rock is crushed between the mantle and a bowl liner. The mantle has a substantially frusto conical shape with an opening at a small diameter end. The opening has a tapered surface that decreases in diameter in a direction toward a large diameter end of the mantle. The mantle is attached to the cone head by a torch ring (a washer) that contacts the tapered opening of the mantle, and a mantle nut that passes through the washer and threadingly engages a mantle bolt. A protective mantle nut cap/feed plate overlies and is normally bolted to the mantle nut. The mantle and mantle nut are typically spot welded in two or three locations to the torch ring.
The mantle requires regular replacement due to wear. In order to replace a worn mantle, the mantle nut cap is removed, and the torch ring cut with an oxy torch. The cutting of the torch ring enables the mantle nut to be more easily removed. In order to now lift the mantle from the cone head, lifting lugs are welded onto the mantle. The lugs are generally manufactured on site using readily available materials which are unlikely to be load rated. Due to the type of steel used in the manufacture of mantles, the welding process requires specialised procedures and welding consumables otherwise the weld will become brittle and fail. There have been many instances over the years where mantles have detached from the lugs during lifting due to poor quality welding creating substantial hazard and causing injuries such as amputation of feet.
While new mantles are often provided with lifting points cast into them, some need to be cut off before use while others simply wear away during use. The present invention was developed to provide an alternate mechanism and method for lifting mantles that can be used on a new or worn mantle.
According to one aspect of the invention there is provided a mantle lifting device for facilitating lifting of a mantle provided with an axial opening, the mantle lifting device comprising:
The body may be configured to at least partially fit in the opening and comprise one or more members to selectively engage with and disengage from the opening.
In one embodiment the one or more members may be fixed to the body wherein the mantle lifting device is engaged and disengaged from the mantle by rotation of the body relative to the mantle in respective opposite directions.
In this embodiment the one or more members may extend radially from a circumferential surface of the body.
In an alternate embodiment the one or more members may be selectively extendible from and retractable into the body wherein the mantle lifting device is: engaged with the mantle by locating the body in the opening and extending the one or more members from the body; and, disengaged from the mantle by retracting the one or more members into the body.
The mantle lifting device may comprise two or more members equally spaced about the body.
The lifting point may comprise a lug coupled to an upper surface of the body.
The mantle lifting device may comprise a releasable locking mechanism for locking the body when engaged with the mantle against disengagement from the mantle.
The releasable locking mechanism may comprise a bolt movable supported on the device the bolt being selectively movable into and out of a seat formed in the mantle.
A second aspect of the invention may provide a mantle for a cone crusher comprising:
The circumferential wall of the opening in the mantle may be formed between first and second edges, and the recess comprises a first portion that extends axially between the first and second edges, and a second contiguous portion which extends circumferentially and under cuts the first edge.
A third aspect of the invention may provide a method of lifting a mantle comprising:
An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:
The mantle lifting device 10 comprises a body 26 which is configured to selectively engage and disengage the opening 24 of the mantle 12 by rotation in respective opposite directions about a central axis 28 of the body 26. When the body 26 is aligned with the hole 24, the axis 28 coincides with a central axis of the mantle 12. The body 26 is provided with a lifting point 30 which is configured, by virtue of the existence of a hole 32, to couple with a lifting device such as a crane (not shown). Thus, when the mantle lifting device 10 is engaged to lift the mantle 12, and the lifting point 30 is engaged with the lifting device, the lifting device can be operated to lift the mantle. This enables the mantle to be placed on or removed from a cone head of a cone crusher.
The body 26 is in the general form of a plug having an upper planar surface 34 and an opposite planar surface 36 and two tapered circumferential surfaces 38 and 40. The circumferential surface 38 is contiguous with the upper surface 40 while the circumferential surface 40 is contiguous with the bottom surface 36. The surfaces 38 and 40 are contiguous with each other and meet to form a circumferential edge 42 which defines the largest diameter of the device 10. The surface 40 is provided with indicia 43 in this instance a coating of paint commencing at a distance d on the surface 40 below the edge 42. This is used to indicate safe or unsafe lifting conditions. The indicia 43 being visible when the device 10 is engaged with the mantle 12 is an indication that the mantle 12 is worn to the extent that it may not be safe to lift the mantle 12 by way of the device 10, or at least not without additional safety precautions being taken.
When the device 10 is seated in the opening 24, the edge 42 lies adjacent an upper edge 44 of the opening 24. An inner circumferential surface 46 of the opening 24 is bound by the edge 44 and a lower edge 47 of smaller diameter. Thus the surface 46 tapers in diameter in a direction from edge 44 toward edge 47. The tapering of the surface 46 is complimentary to the tapering of the surface 40 on the device 10 so that there is substantially face to face contact between the surfaces 40 and 46 when the device 10 is engaged in the opening 24.
The device 10 is provided with, in this embodiment, four members 48 that extend generally radially from the circumferential surface 40. The members 48 are configured to fit in corresponding recesses 50 formed in the opening 24 and more specifically in the surface 46. Each recess 50 comprises a first portion 52 that extends in an axial direction from upper edge 44 to the lower edge 47. The recess 50 also comprises a second portion 54 which is contiguous with the first port 52 and extends in a circumferential direction undercutting the upper edge 44.
In order to engage the device 10 with the mantle 12, the device 10 is placed into the opening 24 with the members 48 aligned with the first portion 52 of the recesses 50. When the device 10 is seated in the opening 24 with the surfaces 40 and 46 in mutual contact, the device 10 can then be rotated in an anticlockwise direction so as to locate the members 48 in the second portion 54 of the recesses 50. The device 10 is now engaged with the mantle 12. Thus the mantle 12 can be lifted by connecting the device 10 via the lifting point 30 to a lifting device such as a crane. Once the mantle 12 has been lifted and placed in a desired location, the device 10 can be disengaged by simply rotating the device 10 in a clockwise direction so that the members 48 are aligned with the first portions 52 of the recesses 50. The degree of rotation required to engage and disengage the device 10 is less than 180° and in one embodiment may be between say 10°-30°.
In order to minimise the risk of accidental disengagement of the device 10 from the mantle 12 during a lifting operation, a locking mechanism 56 may be incorporated in the device 10. In one embodiment the locking mechanism 56 comprises a bolt or pin 58 that can be moved into an out of a seat 60 formed in the opening 24 of the mantle 12. The seat 60 may coincide with the first portion 52 of one of the recesses 50. The mechanism 56 comprises a right angle arm having an upper arm 62 which is pivotally connected at one end to a bracket 64, with the bolt 58 extending at right angles to and from an opposite end of the upper arm 62. When the members 48 are located in the second portion 54 of a respective recesses 50, the bolt 58 can be dropped into the seat 60 by pivoting of the arm 56 to lie the upper arm 62 against the upper surface 34 of the body 26. This prevents rotation of the device 10.
In a variation the plug 10′ can be dimensional and/or configured so that the members 48, when extended from the body 26, lie beneath the lower edge 47 of the opening 24 in the mantle 12. In this variation of the mantle lifting device, the device may be used with a mantle which is not provided with recesses 50.
The mantle lifting device 10′ may also be provided with a locking mechanism to releasably lock the device 10′ in the engaged position.
As explained below some of these differences also result in a different configuration of mantle 12″ in order to enable use of device 10″. These differences are described as follows. Upper surface 34 and device 10″ has a generally concaved configuration as shown clearly in
The configuration of the circumferential surface of device 10″ is also different to that of the other embodiments. In device 10″, circumferential surface 40 extends between upper and lower surfaces 34 and 36. However, as most clearly shown in
In addition to being dished, upper surface 34 is provided with a central boss 112, and two diametrically opposed smaller bosses 114. As shown in
Device 10″ also incorporates a jack system 124. The jack system 124 comprises bolts 126 threadingly engaged in axial through holes 128 formed through bosses 114. Jack system 124 is operable to extend from lower surface 38 of body 26. This is achieved by screwing down the bolts 126 so that respective shanks of bolts 126 can protrude below surface 38. This assists in breaking a seal between mantle 12″ and a cone head of a corresponding cone crusher. In addition jacking system 124 may assist in turning the device 12″.
Releasable locking mechanism 56 of device 10″ comprises a pin 130 that is biased to extend radially from circumferential surface 40 and is retractable in opposition to the bias for example by pulling on a knob 132 attached to pin 132. Pin 132 slides within a hole 134 formed in a pin housing 136 which in turn is integrally formed with body 26.
Now that an embodiment of the present invention has been described in detail it will be apparent to those skilled in the relevant art that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, the embodiments depict the use of four members 48 in the device 10 for engaging the mantle 12. However a different number of members 48 may be used for example one, two or three. While one member 48 can be used, it is believed that safety will be enhanced by the provision of at least two members 48. When there is more than one member 48, the members 48 may be equally spaced about the circumferential surface 40 of the body 26. In a further variation the body 26 need not be in the form of a plug as illustrated in the drawings, but can for example be in the form of a ring or annulus with one or two lifting lugs extending either axially from an upper surface or radially from an inner circumferential surface. The lifting point 30 is described and illustrated as a lug fixed to or integrally formed with the body 26. But in an alternate embodiment the fixing point can be demountably coupled to the body 26. For example the fixing point may be in the form of a pin provided with an eye at one end to engage a lifting device and a screw thread at an opposite end which screws into a threaded hole formed in the body 26.
All such modifications and variations are deemed to be within the scope of the present invention the nature of which is to be determined from the above description.
Number | Date | Country | Kind |
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2009904290 | Sep 2009 | AU | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AU10/01145 | 9/3/2010 | WO | 00 | 6/26/2012 |