Field of invention

The present invention relates to a gyratory crusher shell lifting device and in particular, although not exclusively, to a device in which pivotable clamping arms are capable of automatic engagement of a crusher shell as the device is lowered downwardly into position.

Background art

Gyratory crushers are used for crushing ore, mineral and rock material to smaller sizes. Typically, the crusher comprises a crushing head mounted upon an elongate main shaft. A first crushing shell (typically referred to as a mantle) is mounted on the crushing head and a second crushing shell (typically referred to as a concave) is mounted on a frame such that the first and second crushing shells define together a crushing gap through which material to be crushed is passed. A driving device positioned at a lower region of the main shaft is configured to rotate an eccentric assembly about the shaft to cause the crushing head to perform a gyratory pendulum movement and crush the material introduced in the crushing gap-

The inner and outer shells are heavy wear parts typically of the order of half a metric ton or more. To facilitate manoeuvring of the shells into and from their position within the crusher frame it is common to weld lifting eyelets to an upper annular edge of the shell enabling an auxiliary lifting crane to suspend the shell via chains or the like. Following installation, with the shells lowered into position, the lifting eyelets may then be removed using a cutting torch.

To facilitate insulation and replacement of the shell wear parts, EP 14160405.8 describes a gyratory crusher shell lifting tool that obviates the need for attachment and removal of lifting eyelets. The tool comprises pivoting arms configured to extend and retract radially relative to a central hub to engage a radially inward facing (crushing) surface of a concave to allow the shell to be engaged by the lifting crane. However, there exists a need for a shell lifting device that offers further advantages to facilitate installation and interchange of crushing shells. In particular, the lifting tool of EP 14160405.8 requires service personnel to reach or climb into the shell interior to both release and engage the locking mechanism that controls the pivoting arms. This manual intervention represents a safety hazard with personnel located directly below the heavy lifting crane and suspension chains etc.

Additionally, the tool typically requires manual adjustment so as to be centered within the shell to align the arms correctly for secure engagement onto the shell inner surface. In particular it is not uncommon for personnel to be required to climb into the shell to manoeuvre the tool into position. Accordingly, what is required is a device that facilitates engagement and release of the shell and the installation and replacement procedure generally.

Summary of the Invention It is an objective of the present invention to provide a gyratory crusher shell lifting device that greatly facilitates the movement (in particular raising and lowering) of gyratory crusher shells during installation and servicing procedures. In particular, it is a specific objective to provide a shell lifting device that minimises manual intervention as the lifting tool is lowered into position and engages the shell to avoid personnel being required to lean into the shell and occupy the region immediately under auxiliary lifting apparatus. It is a further specific objective to provide a lifting device that automatically engages the shell as it is lowered into position and automatically centers and aligns itself within the shell immediately prior to and during engagement with the shell to provide secure and reliable lifting.

The objectives are achieved by providing a lifting device in which a plurality of lifting arms are capable of automatically pivoting at least radially outward as the device is lowered into position within the shell. In particular, the device comprises a lowermost ground engager that is configured to force shell engaging portions of the arms radially outward into contact with a radially inward facing surface of the shell as the device is lowered into contact with the ground or an intermediate support structure on which the shell is mounted immediately prior to lifting. Accordingly, the present lifting device does not require service personnel to release a locking mechanism to allow the arms to engage the shell as this occurs simultaneously on lowering the device into contact with the ground and the shell. According to a first aspect of the present invention there is provided a gyratory crusher shell lifting device for lifting a gyratory crusher shell comprising: a hub positioned on a central axis of the device and having a first lift element to hang the device from auxiliary lifting apparatus; a plurality of arms mounted at the hub via respective pivot mountings, an axially lower portion of the arms extending axially downward and to be capable of extending radially outward from the pivot mountings and having radially outward directed shell engaging portions positioned at or towards an axially lower lengthwise end of the arms to contact a radially inward facing surface of a gyratory crusher shell; at least one ground engager positioned axially below the lower portion of the arms when the device is in an inoperative mode in which the shell engaging portions are pivoted radially inward relative to the hub; characterised in that: the at least one ground engager is configured to contact the ground when the device is lowered axially into the gyratory crusher shell to cause the arms to pivot about the pivot mountings and adapt the device from the inoperative mode to an operative mode in which the shell engaging portions are pivoted radially outward relative to the hub.

Preferably, the arms comprise axially upper regions that extend axially upward and radially outward from the pivot mountings at least when the device is in the inoperative mode, the axially upper regions configured to pivot radially inward towards the central axis when the device is adapted from the inoperative mode to the operative mode. Optionally, the axially upper regions may be configured to extend axially upward and radially outward from the pivot mountings such that an axially upper lengthwise end of the arms is positioned radially outside the hub so as to be accessible at least when the device is in the operative mode. Advantageously, the arms comprise a length between the respective axially lower and upper ends that extend axially upward and radially outward from the hub so as to project axially and radially outward from the upper annular rim of the shell to enable convenient attachment of suspension chains immediately prior to lifting. Accordingly, service personnel are not required to position themselves immediately over or into the shell when readying the device and shell for secure lifting. Moreover, the upper ends extending axially upward and radially outward from the hub acts to maximise the clamping force by which the shell engaging portions are forced and maintained in contact with the inner surface of the shell in the operative mode. Additionally, the radially outward extending upper arm regions are also configured to engage the upper annular rim of the shell (for certain shell geometries) as the device is lowered. This acts to actuate an initial radially outward pivoting of the shell engaging portions towards the shell inner crushing face. This initial arm pivoting action is facilitated by configuring the arm upper regions with a curvature or angled orientation relative to the longitudinal axis of the device.

Preferably, the axially upper regions of the arms comprise second lift elements connectable to the auxiliary lifting apparatus to lock the arms relative to the hub when the device is in the operative mode. Such an arrangement is advantageous to enable the device to be suspended from auxiliary lifting apparatus via the arms either exclusively or in

combination with suspension via the central hub. When suspended via the arms, the device is locked in the operative mode as the hanging weight of the crusher shell and the device from the second lift elements forces the shell engaging portions into contact with the inward facing surface of the shell. The strength of the force of engagement of the shell by the device is therefore proportional to the weight of the heavy crusher shell in combination with the present lifting device. Optionally, the device further comprises bias members connected between the arms and the hub to bias the shell engaging portions to pivot radially inward in the inoperative mode. Preferably, the bias members comprise springs and in particular coil springs. The springs are preferably mounted between the hub and the axially upper regions of the arms and comprise a return force to assist the folding/pivoting of the arms from the inoperative position to the operative position. Such a configuration is advantageous to facilitate the change of the device from the inoperative mode to the operative mode as the ground engager contacts the ground and the upper regions of the arms are journaled to collapse radially inward into the hub. Preferably, the pivot mountings are positioned in a lengthwise direction of the arms closer to the lower lengthwise end of the arms relative to the upper lengthwise end of the arms. Optionally, the axially lower regions of the arms comprise a length that is in the range 10 to 60%, 10 to 50%, 10 to 40%, 15 to 30% or more preferably 20 to 30% of a length of the axially upper regions of the arms. Accordingly, in the inoperative mode, the axially upper portions of the arms extend radially outward beyond the axially lower portions of the arms to maintain the device in the inoperative mode when suspended from the auxiliary lifting apparatus via the hub. The relative positioning of the pivot mountings along the length of the arms facilitates the pivoting of the arms as the device is changed between the operative and inoperative modes due to the weight of the arms at the different regions.

Preferably, each of the arms is elongate having a main length as defined between the axially lower end and the axially upper end that is generally angular or arcuate in the axial direction (relative to the longitudinal axis of the device) such that the axially lower and upper ends project radially outward relative to the hub. That is, preferably each arm is curved or angled along its length such that the axially upper and axially lower ends are directed radially outward to comprise a generally U-shaped length configuration.

Alternatively, the arms may comprise hook- shaped length profiles with the pivot mountings positioned at the mid to lower region of the hook between the lengthwise upper and lower ends of the arms. The curved configuration of the arms is advantageous to position the axially upper regions of the arms that extend axially upward and radially outward beyond the upper annular rim of the shell when the device is in the operative mode. Accordingly, service personnel are capable of gaining unhindered access to the second lift elements provided at each arm for the convenient attachment of lifting chains and the like ready for lifting of the device and the shell by the auxiliary lifting apparatus. Service personnel are not therefore required to position themselves immediately under a lifting crane and to lean or climb into the shell to attach the lifting chains and configure the device in a locked state for secure and reliable lifting. Advantageously, the present device does not comprise an additional locking mechanism in that the locking of the shell engaging portions of the arms is achieved by suspending the device from the auxiliary lifting apparatus via each of the arms. The present device is therefore self-locking under the weight of the crushing shell. Advantageously, mounting the second lift elements radially outward beyond the hub and in particular the shell, increases the force of contact between the shell engaging portion of the arms and the inner surface of the shell.

Accordingly, a radial length of the axially upper portions of the arms is configured such that the axially upper ends of the arms (where the second lift elements are mounted) are positioned radially at a position above or outside the upper annular rim of the shell when the device is mounted centrally within the shell internal cavity.

Optionally, the at least one ground engager comprises a base suspended below the hub and having a downward directed ground engaging part, the base movably connected to each of the arms via radially outward extending pivotable link members. To facilitate the configuration of the device to change between the operative and inoperative modes, preferably, the link members extend radially outward from the base to the arms at an orientation such that the hub and the lowermost regions of the arms are capable of moving axially downward to the base under the force of gravity on contact by the ground engaging part with the ground to force the shell engaging portions radially outward and to adapt the device between the inoperative mode and an operative mode. Optionally, in the inoperative mode, the link members extend radially outward relative to the axis at an angle greater than 10, 20 or 30°. Optionally, the at least one ground engager may comprise a fixed or moveable (pivotally mounted) strut, member of actuator projecting downwardly from each arm to contact the ground as the device is lowered into the shell and assist or provide the pivoting action of the arms. Preferably, the first and second lift elements comprise lift eyelets and/or suspension chains, cable or rope. Preferably, the device further comprises a suspension assembly to suspend the device from the auxiliary lifting apparatus, the assembly comprising a first suspension element to extend between the auxiliary lifting apparatus and the first lift element at the hub and a set of second suspension elements to extend between the auxiliary lifting apparatus and the second lift elements at the arms such that the device is configured to be suspended from the auxiliary lifting apparatus via the hub in the inoperative mode and to be suspended at least from the auxiliary lifting apparatus via the arms in the operative mode. The suspension assembly is specifically configured for attachment to the arms only when the device is correctly adapted in the operative mode. This is achieved, in part, via the assembly further comprising spacers extending between each of the second suspension elements to maintain a separation distance between the second suspension elements so as to align the second suspension elements with each of the second lift elements at the arms when the device is on the operative mode. Accordingly, the suspension assembly via the spacers provides a safety condition to prevent inappropriate lifting of the device and the shell when the device is not orientated/aligned correctly within the shell and the upper regions of the arms are not collapsed radially inward to the desired extent. Optionally, the spacers comprise cables surrounded by elastomer bushings so as to be flexible, semi- flexible, rigid or semi-rigid in a direction between the suspension elements. Preferably, the first and second suspension elements comprise chains, cables, belts and/or rope. As will be appreciated, the suspension elements may comprise rigid or flexible members having a strength suitable to suspend the device and the gyratory crusher shell from the auxiliary lifting apparatus. Preferably, the axially upper ends of the arms extend radially outward beyond the axially lower ends of the arms when the device is in the inoperative and operative modes. Such an arrangement is advantageous to facilitate access to the second lift elements at each arm and the attachment of the device to the suspension assembly and in particular the auxiliary lifting apparatus. Service personnel are therefore able to keep a safe distance from the region immediately under a lifting crane and the attachment chains or belts. Such an arrangement also actuates/facilities pivoting of the arms as the upper region of the arms contact an upper annular rim of the shell (for certain configurations of shell) as the device is lowered into the shell.

Preferably, the device comprises three arms pivotally mounted at the hub and spaced apart circumferentially around the axis by a uniform separation distance. Such an arrangement is advantageous to facilitate automatic alignment of the device within the shell and in particular the secure engagement of the shell engaging portions of the arm onto the inward facing surface of the shell. A three point contact configuration avoids misalignment of the device within the shell and the need for service personnel to intervene manually and readjust the position of the device prior to lifting. The present device is accordingly advantageous to provide a fully automated or partially automated lifting device that minimises manual intervention and the health and safety risks presented to service personnel. Optionally, the shell engaging portions are formed integrally with the arms or may be formed as separate components removably attached to an end region of each arm so as to be a wear part.

Brief description of drawings

A specific implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:

Figure 1 is an upper perspective view of a gyratory crusher shell lifting device comprising a plurality of pivoting arms centered around a hub and suspended via a suspension assembly according to a specific implementation of the present invention; Figure 2 is an underside perspective view of the shell lifting device of figure lin an inoperative mode ready for introduction and engagement at a gyratory crusher shell; Figure 3 is a magnified perspective view of the central hub and a part of one of the pivoting arms with selected components removed for illustrative purposes according to a specific implementation of the present invention; Figure 4 is a further perspective view of the shell lifting device of figure 1 in an operative mode suitable for engagement at an internal facing surface of a gyratory crusher shell;

Figure 5 is a further perspective view of the shell lifting device of figure 1 in the inoperative mode immediately prior to lowering into an interior region of a gyratory crusher shell;

Figure 6 is a perspective view of the shell lifting device of figure 5 engaged in contact to raise a gyratory crusher shell off the ground; Figure 7 is a further perspective view of the shell lifting device of figure 5 in the operative mode configured to lift a gyratory crusher shell.

Detailed description of preferred embodiment of the invention Referring to figures 1 and 2, a gyratory crusher shell lifting device 100 comprises generally a suspension assembly 101 configured to suspend a shell engaging assembly 102 from auxiliary lifting apparatus. The lifting device 100 enables the lateral (horizontal) and vertical transportation of a gyratory crusher shell within a working environment. In particular in an operative mode the device 100 is configured to engage onto the gyratory crusher shell and an inoperative free hanging mode the device 100 is configured for introduction and removal at the gyratory crusher shell. Figures 1 and 2 illustrate the lifting device 100 in the inoperative mode.

The lifting device 100 comprises a central hub 104 positioned on a longitudinal axis 117 that extends through the entire device 100 including suspension assembly 101 and shell engaging assembly 102. Three elongate arms 103 are pivotally mounted around hub 104 via respective pivot mountings 105 in the form of pivot pins that extend through hub 104 and each arm 103. Each arm 103 is generally elongate comprising a first axially upper end 108 and a second axially lower end 109. Pivot mounting 105 is positioned axially at a lengthwise region of arm 103 between ends 108, 109 substantially towards the second lowermost end 109. Accordingly and referring to figure 2, each arm 103 comprises an axially upper region 200 defined between pivot mounting 105 and upper lengthwise arm end 108. Each arm 103 further comprises an axially lower region 201 defined between pivot mounting 105 and the axially lower lengthwise end 109. According to the specific implementation, a length of the upper region 200 of each arm 103 (between upper arm end 108 and pivot mounting 105) is greater than a corresponding length of the lower region 201 (between pivot mounting 105 and lower arm end 109). In particular, the length of lower region 201 is approximately 25% of the length of upper region 200 between the respective ends 109, 108 and the pivot mounting 105. Each arm 103 is formed by a pair of opposed elongate plates 311 secured together via a plurality of bolts 312 as illustrated in figure 3. Referring again to figure 2, each arm 103 comprises a pair of arcuate edges 203 extending along the inside of the curve of each arm 103 and a corresponding pair of edges 204 extending along the outside of the curve of each arm 103. Accordingly, each arm 103 is generally U- or hook-shaped and is attached to hub 104 towards the lowermost end of the hook (towards lower arm end 109). Accordingly and as illustrated in figure 2, with the device 100 orientated in the inoperative mode, the majority of arm upper region 200 extends radially outward beyond the arm lower region 201. In particular, arm upper region 200 projects radially outward and partially axially upward from hub 104. Each arm therefore is configured to hang with the upper end 108 facing generally axially downward at a radial separation distance from hub 104 that is at least equal to or greater than a diameter of hub 104 in a direction perpendicular to axis 117. Moreover, a distance by which each arm 103 extends in a radial direction, in the inoperative mode, is greater than a distance by which each arm 103 extends in a direction of axis 117. When orientated in the inoperative mode of figures 1 and 2, arm lower region 201 is aligned with axis 117 so as to be approximately vertical and in particular inclined slightly outward such that lower arm end 109 projects radially outside pivot mountings 105 and is orientated generally axially downward.

Device 100 further comprises a base 106 formed as a plate-like body and mounted immediately axially below hub 104. Base 106 is pivotally mounted to each arm lower region 201 via respective link members 107 formed as elongate struts pivotally mounted at base 106 and each respective arm 103. Accordingly, hub 104 is connected exclusively to base 106 via the intermediate arm lower regions 201 and link members 107. As each arm 103 is configured to pivot about pivot mountings 105, hub 104 is capable of being raised and lowered relative to base 106 when base 106 is stationary (for example when base 106 is positioned on the ground). Base 106 comprises a downward facing ground engaging surface 205 configured to contact the ground and at least support device 100 as it is lowered into position within a gyratory crusher shell as detailed with reference to figure 5.

Hub 104 comprises a first lifting eyelet 110 connected via a link 115 to a chain 112 that forms part of the suspension assembly 101. Accordingly, shell engaging assembly 102 is capable of being suspended from suspension assembly 101 via chain 112, link 115, eyelet

110 and hub 104 such that each arm upper region 200 is free hanging to represent radially outermost parts of the device 100. In this configuration, the radially outermost upper arm ends 108 are aligned to extend slightly downward due to the curvature of each arm 103. Each arm 103 further comprises respective second eyelets 111 orientated generally upward and positioned at arm upper ends 108. Suspension assembly 101 further comprises three further chains 113 extending axially downward and projecting radially outward at a declined angle from a common link support 116 to which one end of hub chain 112 is also attached. Each arm chain 113 is terminated at its lower end by a respective link 114 configured to engage each respective arm eyelet

111 when device 100 is adapted in the operative mode with arm upper regions 200 pivoted radially inward towards hub 104 as detailed with reference to figures 4, 6 and 7.

Referring to figure 3, hub 104 comprises a triad configuration in which three shoulders 314 project radially outward from axis 117 towards each respective arm 103. Each shoulder 314 is formed by a pair of opposed plates 301 fixed together via a series of bolts 315. Each of the shoulders 314 are connected via a first 313, a second 302, a third 303 triad plates separated axially along the axial length of hub 104. Eyelet 111 is connected to an upper face of the uppermost triad plate 313. Device 100 further comprises three bias springs 300 mounted to extend between hub 104 and each arm 103. In particular, each spring 300 is mounted at hub 104 via axel 304 extending between hub plates 301 and is mounted at each arm 103 via axel 305 extending between arm plates 311. Springs 300 are configured to bias each arm upper region 200 into an axially collapsed position towards hub 104 in a radial direction away from the radially outward orientation of the inoperative mode of figures 1 and 2. That is, springs 300 are configured to pull arm upper regions 200 and arm upper ends 108 radially inward towards hub 104 and axis 117. Springs 300 therefore assist with the folding of the arms 103 from the device inoperative mode to the operative mode and engaging contact with the gyratory crusher shell. Figure 3 further illustrates the connection of base 106 to each arm 103 via link members 107. In particular, a first radially inner end of link member 107 is attached to base 106 via pivot pin 306 and is attached at a radially outermost end to arm 103 via a corresponding pivot pin 307. Each arm 103 is reinforced at the lower end 109 via a pair of engaging plates 308. A generally radially outward facing edge 310 of each plate 308 defines a shell engaging portions of each arm 103 configured to engage a radially inward facing surface of the crusher shell as detailed below.

Referring to figure 4, shell engaging assembly 102 is capable of being suspended via each of the arms 103 when adapted in the operative mode with the arm upper regions 200 collapsed radially inward towards axis 117 and hub 104. To ensure device 100 is suitable to be suspended from the suspension assembly 101 via arm chains 113 and arms 103, suspension assembly 101 comprises three elongate spacers 400 that extend generally perpendicular to axis 117 between the lower regions of each arm chain 113. According to the specific implementation, each spacer 400 comprises a metallic cable core surrounded by an elastomer so as to be semi-flexible but importantly to maintain a predetermined separation distance between the arm engaging links 114. In particular, each spacer 400 is positioned axially between each arm chain 113 and arm chain link 114 via an intermediate chain linkage 401 and 402. Coupling links 114 to arm eyelets 111 only when spacers 400 are straight ensures the device 100 is appropriately configured in the operative mode with the arm engaging portions 310 mated in full frictional contact with the internal facing surface of the shell and as such the upper arm ends 108 translated sufficiently radially inward. Ref erring to figures 5 to 7, and in operation, device 100 is suspended from auxiliary lifting apparatus 600 via a belt support 601 coupled immediately above link support 116 that forms a part of the suspension assembly 101. Arm links 114 are not coupled to the arm eyelets 111 to allow the arm upper regions 200 to hang in their radially outermost positions as illustrated in figures 1 and 2 under gravity. Accordingly, base 106 hangs axially below shell engaging portions 310 corresponding to the axially lowermost end 109 of each arm 103. In such a configuration, each link member 107 extends at an inclined angle relative to axis 117 in the range 20 to 40°. Such a configuration is advantageous to ensure the arms 103 pivot readily about pivot mountings 105 as hub 104 is allow to fall under gravity towards base 106 when the base surface 205 contacts the ground 506.

Gyratory crusher shell 500 comprises an annular configuration having a radially outward facing surface 504 and a radially inward facing surface 503 defining an internal cavity 502. The shell wall is terminated at its upper end by an annular rim 501 and at an opposite end by an axially lower annular rim 505. With the shell 500 mounted upon the ground 506, lifting device 100 is lowered axially into shell cavity 502. With a shell configuration as illustrated in figures 5 to 7, base 106 is lowered within cavity 502 to contact ground 506 prior to arms 103 engaging upper annular rim 501. Due to the orientation of link arms 107 and the relative positioning of pivot mountings 105 along the length of each arm 103, arms 103 are adapted to pivot under the weight of device 100 automatically. As the arm upper regions 200 collapse radially inward towards axis 117, hub 104 falls axially downward towards base 106 and link members 107 lean progressively to a more horizontal orientation as illustrated in figure 4. In the fully collapse configuration of figure 4, base 106 is positioned immediately below hub 104 with little or no axial separation (between axially lower parts of hub 104 and axially upper parts of base 106). With arms 103 collapsed radially inward to the position of figure 4 from the position of figure 1, the suspension assembly 101 may then be coupled to via eyelets 111 and links 114 at the uppermost arm ends 108. The coupling between eyelets 111 and links 114 requires manual intervention. However, as arms 103 project axially upward and radially outward from hub 104 personnel are not required to position themselves directly below suspension belt 601 and auxiliary lifting apparatus 600 and can maintain a safe distance to reduce health and safety risks. Additionally, each arm 103 is configured to project axially and radially outward from shell cavity 502 (and upper rim 501) which also greatly facilitates the couplings of arms 103 to the suspension assembly 101 as personnel are not required to lean or climb into the shell cavity 502 unlike conventional lifting devices.

Moreover, the configuration of the arm upper regions 200 extending radially outward from axis 117 and in particular pivot mountings 105 is advantageous to provide a desired loading force by which each arm engaging part 310 is forced into frictional contact with shell inner surface 503 when suspended from the auxiliary lifting apparatus 600 as illustrated in figures 6 and 7. In particular, each arm chain 113, when device 100 is adapted in the operative mode is illustrated in figure 6, extends at an angle of

approximately 25° relative to axis 117 and hub chain 112. As will be appreciated, the tensile force within each arm chain 113 is translated as a compressive force by which shell engaging part 310 engages shell inner surface 503. The device comprising three lifting arms 103 is advantageous to both facilitate the centering and alignment of the device 100 within shell 500 (as the shell engaging parts 310 are pivoted radially outward onto shell inner surface 503) and also to maximise the force by which engaging parts 310 clamp onto the shell inner surface 503. Accordingly, the present device is advantageous in its configuration such that the strength of the engagement of the shell 500 by the shell engaging parts 310 is proportional to the weight of the shell 500. Such an arrangement is also advantageous to obviate the need for additional locking mechanisms as the arms 103 are locked automatically via coupling and suspension from the suspension assembly 101 and the lifting apparatus 600.