Patent Application
20210308688
The present invention relates to a crusher mantle lifting device. The invention also relates to an arrangment comprising such a lifting device in combination with a crusher mantle, and to a method for attaching such a lifting device to a crusher mantle.
Gyratory crushers generally comprise a concave surface and a conical head. The inner cone has a slight circular movement, generated by an eccentric arrangement and as such it does not rotate. Material to be crushed travels downward between the two surfaces being progressively crushed until it is small enough to fall out through the gap between the two surfaces. Gyratory crushers are typically designated in size either by the gap and mantle diameter or by the size of the receiving opening. The crushing action is caused by the closing of the gap between the moveable mantle mounted on the main shaft and the fixed concave liners mounted on the main frame of the crusher. The gap is opened and closed by an eccentric on the bottom of the spindle that causes the central vertical spindle to gyrate.
When installing the mantle of a gyratory crusher supported only by backing material, the mantle is lifted by means of a lifting tool, typically a hydraulic lifting tool, against a head nut of the crusher for a correct height positioning, such that the upper part of the mantle is in contact with the head nut throughout the circumference of the mantle. Similarly, a worn out mantle which needs to be replaced is lifted by means of such a lifting tool. Commonly, new mantles which are to be installed to the gyratory crusher are provided with cast lifting lugs. A hydraulic lifting tool may, for instance by means of chains attached to the lifting lugs, lift the mantle into place. When the mantle has been correctly installed the lifting lugs are removed before operation of the gyratory crusher. Worn mantles are uninstalled and lifted by subsequently adding new lifting lugs which are welded to the mantles. Welded lifting lugs are a risk as there is usually only a visual inspection of the welds before lifting. This is not only a safety risk, but also a time consuming procedure. Furthermore, for both the original lifting lugs and the welded lifting lugs there is no locking system for the lifting chains, which also entails a safety risk. These considerations do not only apply to gyratory crusher mantles, but also other crusher mantles such as cone crusher mantles.
U.S. Pat. No. 5,323,976 discloses a mantle having recesses. Lifting brackets may be connected to the mantle by a simple bolt and nut fixation at the recess. In an alternative embodiment, lifting hooks are simply inserted into the recesses. Although both of these alternatives avoid the time consuming operation of removing lifting lugs and welding new lifting lugs to a mantle, these simple connections to the mantle are far from satisfactory from a safety perspective.
There is still a need for a solution to lifting a crusher mantle which is satisfactory both from a safety perspective and a time consumption perspective.
It is an object of the invention to mitigate the drawbacks of the known solutions for lifting a crusher mantle. This and other objects, which will become apparent in the following, are accomplished by means of a lifting device as defined in the independent claim.
The present invention is based on the realization that a locking portion which protrudes into an opening of a mantle for transmitting a lifting force into the mantle may be locked in place by two different pressing means, resulting in increased safety and still allowing for a time efficient lifting procedure. In particular, it has been found advantageous to have such a double-pressed locking portion made integrated or integral with the element that is connected to a lifting tool (e.g. via a chain assembly), rather than having a separate locking solution such as fixating the plate with a bolt which engages a nut in the mantle (such as in U.S. Pat. No. 5,323,976). That being said, it is conceivable to integrate the locking portion to the element by e.g. a threaded connection between the locking portion and the element (which may be advantageous in case the locking portion needs to be exchanged due to wearing). Other options for integrating the locking portion to the element is by welding or shrinking.
According to a first aspect of the invention, there is provided a crusher mantle lifting device. The lifting device may, for instance, be used for a gyratory crusher mantle or a cone crusher mantle. The lifting device comprises:
In the present application certain directional terms are used, including distal, proximal, inner and outer. In particular, the attachment element is sometimes described as having a proximal end and a distal end. The following should therefore be understood; in normal use, when the attachment element is attached to the tapered mantle, a proximal direction is generally along outer surface of the mantle in the direction from the largest diameter of the mantle towards the smallest diameter of the mantle, whereas a distal direction is the opposite direction. Thus, in normal use, the distal end of the attachment element is intended to be located further away from, for instance, a chain suspension of the lifting device (and usually at a lower vertical level) than the proximal end. Thus, when an attachment element is connected to a lifting tool in order to lift the attachment element attached to the mantle, then the lifting force has at least a component directed in the proximal direction of the attachment element. An inner part is intended to be located closer to the centre axis of the mantle than an outer part.
Each attachment element may suitably be shaped to substantially conform to a portion of the contour of the mantle to which it will be attached. The main portion of the attachment may, for instance, be formed as a curved plate, or as several consecutive plate sections forming an angle relative to each other to substantially follow the curvature of the outer surface of the mantle in its circumferential direction.
The first surface of the main portion of the attachment element may also be regarded as a mantle-abutting surface or as an inner surface (since it will be facing the centre axis of the mantle when the attachment element has been attached to the outer surface of the mantle. Correspondingly, the second surface of the main portion of the attachment element may also be regarded as an outer surface. In other words, as seen from a centre axis of the mantle to which the attachment element is to be attached, the first surface is configured to be located at a smaller radial distance to the centre axis than the second surface, when the attachment element is attached to the outer surface of the mantle.
Since the attachment element may substantially follow the curvature of the mantle in its circumferential direction, in at least some example embodiments, the first surface of the main portion may be a generally concave surface, and the second surface may be a generally convex surface. It should be understood that the expressions “generally concave surface” and “generally convex surface” does not mean that the surfaces have to form a curvature without straight lines. Rather, as explained above, the surfaces may be formed by several consecutive straight sections, wherein each section is provided at an angle to the neighbouring section or sections.
The locking portion may in some embodiments be made in one piece with the main portion, while in other embodiments it may be integrally connected to the main portion of the attachment element, e.g. by means of a threaded connection by welding or shrinking. The locking portion is configured to project from the first surface inwardly, suitably towards the centre axis of the mantle. The locking portion may suitably be centred with respect to a transverse direction of the first surface (which will substantially conform with the circumferential direction of the mantle when the attachment element is attached to the mantle). The transverse direction may suitably be perpendicular to both the proximal-to-distal direction and the inner-to-outer direction.
In at least some example embodiments the locking portion is located proximally of the tightening means. In at least some example embodiments, the locking portion is located distally of said lifting point on which a lifting force is exertable. Although one locking portion per attachment element may suffice, it is also conceivable to have two or more locking portions for protruding into respective openings in the mantle.
Although one lifting portion may suffice, each attachment element may suitably be provided with at least two lifting portions. The lifting portions projecting outwardly (i.e. radially away from the centre axis of the mantle) may suitably be spaced apart for improved stability and load distribution. The lifting portions may suitably be spaced apart in the transverse direction. According to at least one example embodiment, each attachment element comprises two lifting portions projecting from the second surface of the main portion at opposite sides of a centre symmetry axis of the attachment element extending from the distal end to the proximal end of the main portion.
Each lifting portion define a lifting point on which the lifting force is exertable by the lifting tool. In practice the lifting point may be regarded as an area of the lifting portion. For instance, it may be an area with which a chain assembly (or other type of traction assembly, such as wire, cable, rod, etc.) is engaged. For instance, the outwardly projecting lifting portion may be provided with a through hole to which the chain assembly or the like may be engaged, e.g. by a pin of the chain assembly extending through the through hole. A proximal area of a through-hole defining surface would then normally be subjected to the lifting force transmitted via the pin. That proximal area would be considered a lifting point. Thus, according to at least one example embodiment, each of the one or more lifting portions comprises a through hole located at the lifting point.
According to at least on example embodiment, the crusher mantle lifting device further comprises a main lifting element and a chain assembly, wherein the chain assembly connects each lifting point of the one or more lifting portions to the main lifting element. According to at least one example embodiment, the main lifting element has receiving means, such as holes, for receiving an end portion of a chain, wherein the distance between the receiving means is shorter than the top diameter of the mantle to which the attachment elements are configured to be attached. This ensures that, in operation, the chains will extend from the lifting points of the attachment elements towards the receiving means at an inclination approaching the centre axis of the mantle. This will further enhance the pressing of the locking portions inwardly towards the mantle centre.
It should be understood that since the lifting portion is projecting from the second surface, and the lifting point is defined by the lifting portion, the lifting point will be spaced from the main portion. In other words, seen in a radial direction, the second surface is located between the first surface and the lifting point. The radial or outwardly spacing of the lifting point relative to the main portion may depend on e.g. the degree of taper of the mantle to which the attachment element is to be attached, chain lengths, etc.
In practical use, each attachment element is configured to be positioned in relation to the mantle such that a respective lifting force exerted by the lifting tool on each lifting point has a component directed in a proximal direction of the attachment element.
According to at least one example embodiment, the main portion of each attachment element comprises a distal end and a proximal end, wherein each attachment element is provided with a part of the tightening means or with a part for receiving the tightening means, wherein said part is located closer to the distal end than the locking portion. This provides for a pressing force to be arranged distally of the locking portion. As mentioned previously, the one or more lifting points are suitably arranged proximally of the locking portion, which allows a pressing force to be arranged proximally of the locking portion. The double pressing of the locking portion into the opening of the crusher mantle is particularly advantageous when applied from two sides of the locking portion, i.e. both proximally and distally.
The pressure applied by the tightening means is reflected in at least one example embodiment, according to which said tightening means is configured to press each of the two or more attachment elements towards the outer surface of the crusher mantle by exerting pressure on said attachment element distally to said locking portion and said one or more lifting portions.
According to at least one example embodiment, the tightening means comprises a tightening element configured to be disposed around a circumference of the crusher mantle and the two or more attachment elements. Thus, the tightening means may be arranged to encircle the attachment elements when attached to the crusher mantle, and to exert a radially compressive force. The inwardly directed force applied to the second surface of the main portion of the attachment element will be transmitted to the locking portion of the respective attachment element which will be pressed towards the mantle centre. Although such a compressive force may be provided by different tightening means, including naturally or spring-biased means, in at least some example embodiments the tightening element may suitably be in the form of a tightening strap, a wire or a chain.
The previously discussed part of the tightening means or part for receiving the tightening means may suitably be a holding portion of the attachment element. Thus, according to at least one example embodiment, each attachment element comprises a holding portion projecting from the second surface of the main portion, wherein the holding portion defines a loop, through hole, or a recess, configured to hold the tightening element. Thus, according to at least one example embodiment, the holding portion is located distally to said locking portion and said one or more lifting portions. In embodiments that encompass a tightening strap, the strap may be placed to pass through the holding portion, similarly to a belt made to pass through loops of a pair of trousers. The strap may be tightened around the attachment elements and the mantle by conventional means, such as heavy duty buckles and ratchets.
According to at least one example embodiment, the locking portion extends from the first surface at least partly in a proximal direction. Suitably, the extension of the locking portion is such that, when the respective lifting force is supplied by the lifting device, each attachment element is pressed towards the outer surface of the crusher mantle. Thus, it should be understood that the locking portion of each attachment element may have an oblique, non-perpendicular, extension from the first surface of the main portion. In other words, the locking portion may extend at an inclination inwardly and proximally from the first surface.
According to at least one example embodiment, the locking portion is cylindrically shaped, said locking portion being configured to protrude into a corresponding cylindrical opening in the outer surface of the crusher mantle when attached. The cylindrically shaped locking portion may suitably be solid. Although a cylindrically shaped locking portion is advantageous from a strength perspective, differently shaped locking portions are also conceivable, such as polygonal (for instance for providing a rotational locking). The diameter of the locking portion and the corresponding opening in the mantle may be chosen based on factors, such as weight and size of the mantle. The locking portion may suitably, but not necessarily, have a diameter which is greater than the thickness of the main portion of the attachment element (i.e. the distance between the first surface and the second surface).
According to a second aspect of the invention, an arrangement is provided. The arrangement comprises:
The crusher mantle man be provided with said openings in the outer surface at the time of manufacturing of the mantle. However, it is also conceivable to subsequently create such openings on already existing crusher mantles.
Some crusher mantles may have varying degrees of taper of the outer surface. For instance, from the end having the largest diameter (normally the lower end) towards an intermediate geometrical plane parallel with the ends of the mantle, the outer surface of the mantle may have a relatively smaller degree of taper. Furthermore, the outer surface of the mantle may have a relatively larger degree of taper from said intermediate geometrical plane to the end having the smallest diameter (normally the upper end). This larger degree of taper may on at least some mantles be seen as a bevelled end portion. According to at least one example embodiment, the openings for receiving the locking portions of the attachment elements are provided in a bevelled end portion of the outer surface of the mantle.
It should be understood that the arrangement of the second aspect may be implemented with a system having any functional and/or structural feature or features of the first aspect of the invention.
According to a third aspect of the invention, there is provided a method for attaching a crusher mantle lifting device according to the first aspect of the invention to a crusher mantle, the method comprising:
According to at least one example embodiment, the method further comprises placing a tightening element around the circumference of the crusher mantle and the two or more attachment elements, wherein tightening the tightening means comprises tightening the tightening element by decreasing a circumferential length thereof. Thus, the tightening element may be tightened similarly to tightening a belt around your waist.
It should be understood that the method of the third aspect may be implemented with a system having any functional and/or structural feature or features of the first aspect of the invention. Similarly, the method of the third aspect may be implemented with an arrangement having any functional and/or structural feature or features of the second aspect of the invention.
The mantle 3 is here illustrated as being mounted on a main shaft 7 of a crusher, such as a gyratory crusher. The mantle 3 tapers upwardly from a larger diameter end (not visible) to a smaller diameter end 9. Near the smaller diameter end 9 the angle of taper is increased to form a bevelled end portion 11.
The lifting device 5 comprises two attachment elements 13, which have been attached to the outer enveloping surface of the mantle 3, spaced apart at 180° in the circumferential direction of the mantle 3. However, it is conceivable to have more than two attachment elements 13, such as three or four attachment elements. Suitably, the plurality of attachment elements 13 will be equally spaced around the circumference of the mantle 3.
As can be seen in
The second surface 19 is, at the middle section 15a, also provided with a handle 29 and a loop 31. The loop 31, which can be regarded as forming part of tightening means, is for guiding a tighting element such as a tightening strap 33 illustrated in
Continuing with
As can be seen in
Turning back to
With reference to
Each locking portion 35 will be pressed inwardly towards the mantle centre by two applied forces. On the one hand, the traction force from the chains will press the attachment element 13, and thus locking portion 35 inwardly. The locking portion 35 inserted in the corresponding opening 37 in the mantle 3 may be regarded as presenting a pivot point, which will cause the proximal end 27 of the main portion 15 of the attachment element 13 to be pressed against the mantle 3. Similarly the tightening strap 33 will press the distal end 25 of the main portion 15, and thus also the locking portion 35, inwardly. Thus, the tightening strap 33 exterts pressure on said attachment elements 13 distally to the locking portions 35 and the lifting portions 21.
The skilled person realizes that a number of modifications of the embodiments described herein are possible without departing from the scope of the invention, which is defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 18191728.7 | Aug 2018 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/073241 | 8/30/2019 | WO | 00 |
