GB2576812A - An extraction device and method of use - Google Patents

Abstract

A non-manual device 1 for extracting a blow bar from a rotor assembly (20, fig 4) of an impact crusher (40, fig 10), comprising an engaging means for forcibly extracting the blow bar out of the rotor assembly. The device may be moveably mountable about the rotor circumference, it may comprise a means 2 to locate and secure the device on an impact crusher, where the device may be releasably couplable to a rotor assembly. At least part of the locating and securing means 2 may correspond in shape to a mount of the rotor, and engage the mount by friction, or other fit, there may be at least one or a pair of anchors 5a 5b engaging the mount. There may be a linking means to engage the blow bar projecting from the anchors or a blow bar engagement aperture, the blow bar engaging means 12 may move between retracted and extended positions about a housing 10, via a hydraulically controlled actuator 13. There may be a captivating means 4 securing the device to the rotor such as a lock, latch, or pin. Further disclosed is a means for operating a blow bar extraction device.

Description

AN EXTRACTION DEVICE AND METHOD OF USE

The present invention relates to an extraction device for extracting a component from a machine and in particular to a blow bar extraction device for extracting a blow bar from an impact crusher chamber.

Mobile crushing equipment such as jaw, cone and impact crushers, are used extensively throughout the world for refinement of quarried material and production of aggregates. A typical crusher consists of a hopper where stone material is added to the crusher, a feeder which carries the material to the crushing section, and a crushing apparatus which crushes the material into smaller aggregates.

Generally, the crushing apparatus works by crushing the rocks between two surfaces. The crusher chamber in an impact crusher typically consists of an approximately centrally located rotor assembly that houses one or more ‘blow’ bars clamped firmly in place at various positions around the drum of the rotor assembly. The drum of the rotor assembly is adapted with one or more circumferential mounts for locating and securing a blow bar retainer on the drum of the rotor assembly. The blow bar retainer in turn retains the blow bar in place on the drum of the rotor assembly for interacting with one or more adjustable breaker plates or bars situated along the inner walls of the housing of the crusher chamber.

In use, rock enters the chamber falling onto/into the rotor assembly and breaks. It is then propelled against breaker plates/bars inside the crushing chamber and is further reduced in size by the crushing action between the centrifugal force and subsequent impact force generated by the moment of the blow bars of the rotor assembly and the stationary breaker plates. The output size of the crushed aggregate depends on both the speed with which the rotor assembly spins and the in use gap between the blow bars and the breaker plates.

Over time these components, and in particular the blow bars, become degraded with use. This can adversely affect the productivity of a crushing machine. If the blow bars are not maintained and replaced the gap between them and the breaker plates will not be consistent leading to uncertain quality of output. Furthermore, in a scenario where one blow bar degrades at a quicker rate than the rest of the blow bars attached to the rotor the likelihood of larger pieces of aggregate getting jammed or wedged or the chance of mechanical malfunction or breakage increases. Therefore, replacing the blow bar is an essential piece of maintenance that guarantees the functionality and quality of output in large scale crushing machines.

Currently, blow bars are replaced manually by an engineer. This involves the engineer opening up the crusher chamber and using a tool such as a sledge hammer to dislodge the blow bar from its in use position, i.e. when it is clamped firmly on the drum of the rotor. Although effective, this method requires an amount of skill and strength so not all workers will be able to replace blow bars, it is prone to inaccuracies that can cause mechanical damage to the rotor or the crusher chamber, and it also risks the health and safety of the engineer conducting the repair, or anyone who is in the proximal vicinity whilst the repair is being carried out.

It is an object of the present invention to obviate or mitigate the problems arising from the replacement of blow bars in impact crushers outlined above.

It is a particular object of the invention to obviate or mitigate the problems of causing mechanical damage to the mobile crushing machine, and endangering the health and safety of workers during crusher maintenance/repair.

Accordingly, the present invention provides an extraction device for extracting a blow bar from a rotor assembly in an impact crusher, the extraction device comprising locating and securing means for locating and securing the extraction device on an impact crusher, and a blow bar engagement means movably mountable on the locating and securing means so that the blow bar engagement means is capable of contacting a blow bar for forcibly extracting the blow bar out of a rotor assembly.

Ideally, the extraction device having blow bar engagement means movably mountable on the locating and securing means so that the blow bar engagement means is in alignment with the blow bar at the point of impact for forcibly extracting the blow bar out of the rotor assembly.

Ideally, the extraction device being movably mountable at a plurality of longitudinally spaced positions along the circumference of a rotor assembly so that the blow bar engagement means is in alignment with the blow bar at the point of impact at each of these positions.

Ideally, the locating and securing means of the extraction device being movably mountable at a plurality of longitudinally spaced positions along the circumference of a rotor assembly so that the blow bar engagement means is in alignment with the blow bar at the point of impact at each of these positions.

Ideally, the locating and securing means of the extraction device being movably mountable at a plurality of spaced apart positions parallel to and radially spaced from the longitudinal axis of the rotor assembly along the circumference thereof so that the blow bar engagement means is in alignment with the blow bar at the point of impact at each of these positions.

Ideally, the locating and securing means is adapted to releasably couple the extraction device to a rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to at least one radially extending circumferential mount of a rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to a plurality of radially extending circumferential mounts of a rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to a portion of at least one radially extending circumferential mount of a rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to a portion of a plurality of radially extending circumferential mounts of a rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to a portion of at least one radially extending circumferential mount of the rotor assembly proximal to a blow bar backing bar of a rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to a portion of a plurality of radially extending circumferential mounts of a rotor assembly proximal to a blow bar backing bar of the rotor assembly.

Ideally, the locating and securing means releasably couples the extraction device to a portion of at least one radially extending circumferential mount of a rotor assembly proximal to a blow bar backing bar of the rotor assembly so that the blow bar engagement means is in alignment with the blow bar at point of impact.

Ideally, the locating and securing means releasably couples the extraction device to a portion of a plurality of radially extending circumferential mounts of a rotor assembly proximal to the blow bar backing bar of the rotor assembly so that the blow bar engagement means is in alignment with the blow bar at point of impact.

Ideally, the locating and securing means transversely mounts radially extending circumferential mounts of a rotor assembly.

Ideally, the locating and securing means mounts the extraction device orthogonal to the radially extending circumferential mounts of a rotor assembly.

Advantageously, by mounting the extraction device onto the radially extending circumferential mounts of a rotor assembly in a transverse or orthogonal fashion the extraction device absorbs the impact force exerted by the blow bar engagement member. By absorb we mean generates a reciprocal force to the impact force that counteracts and opposes the impact force. The impact force is absorbed by the innermost facing face of the radially extending circumferential mounts with which the locating and securing means interacts/engages with the corresponding faces of the locating and securing means. The alignment and engagement of the extraction device in relation to the rotor assembly, i.e. transverse or perpendicular, transmits an impact force on the blowbar in the requisite direction of extraction to remove it from the rotor assembly. A reactive force is generated in the opposite direction by the blow bar on the extraction device. By mounting the locating and securing means on the radially extending circumferential mounts perpendicular/transversely, when the reactive force is transmitted into the locating and securing means the locating and securing means moves in the direction of the reactive force, engaging and interlocking with the radially extending circumferential mounts via interference. Further advantageously, a part of the locating and securing means compliments the shape of the radially extending circumferential mounts of the rotor assembly so as to form a corresponding neat fit between the two components.

Advantageously again, by corresponding to the cross-sectional shape of the radially extending circumferential mounts of the rotor assembly, the locating and securing means both anchor the extraction device and provide leverage for it to remove the blow bar in use when extracting the blow bar. By anchor we mean that the locating and securing means prevents the extraction device from moving or dislodging when the blow bar engagement means is actuated to engage the blow bar. By leverage we mean the mechanical advantage the blow bar engagement means uses to forcibly remove the blow bar from its in use position on the barrel of the rotor assembly of the impact crusher. This is generated from the anchoring of the extraction device via the engagement between the locating and securing means and the radially extending circumferential mounts of the rotor assembly,

Ideally, at least part of the locating and securing means corresponds in shape to one or more of the radially extending circumferential mounts of a rotor assembly.

Ideally, at least part of the locating and securing means corresponds in shape to a plurality of radially extending circumferential mounts of a rotor assembly.

Ideally, at least part of the locating and securing means corresponds in shape to the cross-sectional shape of one or more of the radially extending circumferential mounts of a rotor assembly.

Ideally, at least part of the locating and securing means corresponds in shape to the cross-sectional shape of a plurality of radially extending circumferential mounts of a rotor assembly.

In one embodiment, the locating and securing means is manually mounted in situ.

By manually mounted we mean that a mechanical force must be exerted by a user, involving more than pressing a button on a control panel that sends an electric signal, to attach the extraction device to the rotor assembly, i.e. that the extraction device is manually mounted into its in use position by the engineer exerting some sort of physical force to locate and secure the locating and securing means.

In another embodiment, the locating and securing means is automatically operated.

By automatically operated we mean that the extraction device utilizes means to attach itself to the rotor assembly without manual effort, i.e. using an electronic command signaling system to attach the extraction device to the rotor assembly via the rotor assembly attachment means, or no more manual effort than is required to activate a command, prompt, or control means such as pressing a button on a control panel.

Ideally, the locating and securing means mechanically couples to a rotor assembly.

Ideally, the locating and securing means couples to a rotor assembly by engaging one or more radially extending circumferential mounts of the rotor assembly via friction fit, snap fit, interference fit or any other suitable type of fit.

Ideally, the locating and securing means engages the radially extending circumferential mounts of a rotor assembly for captivating the extraction device in situ during operation.

Ideally, the locating and securing means comprises captivating means.

Ideally, the captivating means secures the extraction device to the rotor assembly.

Ideally, the captivating means secures the extraction device to the radially extending circumferential mounts of a rotor assembly.

Ideally, the captivating means secures the extraction device to the radially extending circumferential mounts of a rotor assembly for captivating the extraction device in situ during operation.

Ideally, the captivating means mechanically secures the extraction device to a rotor assembly.

Ideally, the extraction device captivating means releasably secures the extraction device to a rotor assembly.

Ideally, the captivating means secures the extraction device to a rotor assembly via friction lock, snap fit, interference fit or any other suitable type of fit that captivates the extraction device in situ for the purpose of and during operation.

Preferably, the locating and securing means comprises at least one anchor for engaging the one or more radially extending circumferential mounts.

Preferably, the locating and securing means comprises a pair of spaced apart anchors for engaging the one or more radially extending circumferential mounts.

Preferably, the locating and securing means comprises a plurality of anchors for engaging the one or more radially extending circumferential mounts.

Ideally, the anchor is a jaw.

Ideally, the anchor is a fixed jaw.

Ideally, the anchor is a C-shaped fixed jaw.

In one embodiment, the captivating means comprises additional locking means such as some sort of lock, or latch, or pin, or other mechanical coupling means.

Advantageously, this provides further security against the possibility that the extraction device may become dislodged during use and therefore cause damage to the rotor assembly or the impact crusher chamber generally. Further advantageously, the captivating means is releasable so the extraction device can be removed and repositioned to a second position to perform another extraction cycle at a different location along the rotor assembly continuing the blow bar extraction exercise following completion of an extraction cycle in a first position.

By extraction cycle we mean one complete circuit of the actuation of the extraction device, i.e. the extension and retraction of the blow bar engagement means.

Ideally, the locating and securing means comprising releasing means for releasing the additional locking means of the captivating means.

Ideally, the releasing means comprises a releasing mechanism.

Ideally, the releasing means counteracts the effects of the additional locking means of the captivating means.

Ideally, the releasing means counteracts the effects of the additional locking means of the captivating means so that the extraction device is not captivated on the radially extending circumferential mounts of the rotor assembly.

Ideally, the releasing means counteracts the effects of the additional locking means of the captivating means so that the extraction device is still mounted on but not captivated on the radially extending circumferential mounts of the rotor assembly.

Advantageously, the releasing means releases the additional locking means of the captivating means. By this we mean that the releasing means releases the extraction device from captivation on the one or more radially extending circumferential mounts of the rotor assembly by counteracting whatever method the captivating means uses to captivate the extraction device in situ in its operational position. Therefore, the extraction device will remain mounted on the radially extending circumferential mount but not locked on it or the rotor assembly.

Ideally, the releasing means is manually operated.

Ideally, the releasing means is automatically operated.

Ideally, the extraction device comprising extraction device removal means.

Ideally, the locating and securing means comprising extraction device removal means.

Ideally, the extraction device removal means is for removing the extraction device from being mounted on a rotor assembly.

Ideally, the extraction device removal means is for removing the extraction device from being mounted on one or more of the radially extending circumferential mount of a rotor assembly.

Advantageously, the extraction device removal means acts to oppose the force exerted to mount the extraction device to the one or more radially extending circumferential mounts of the rotor assembly. This allows the extraction device to be removed from one position ofthe rotor assembly, i.e. a first radially extending circumferential mount, and be repositioned in a second position, i.e. a second radially extending circumferential mount, to continue or complete the extraction of the blow bar or remove the extraction device from the rotor assembly completely.

In one embodiment, the extraction device removal means is manually operated.

By manually operated we mean that a mechanical force must be physically exerted by an user to release a lever or clasp or any other appropriate captivating means and enable the extraction device to be released from the rotor assembly.

Ideally, the extraction device removal means comprises at least one manually operated handle.

Preferably, the extraction device removal means comprises two manually operated handles.

Ideally, the two manually operated handles are spaced apart.

Advantageously, this enables an operator to remove the extraction device from the rotor assembly using two hands.

In another embodiment, the extraction device removal means is automatically operated.

By automatically operated we mean that the extraction device utilizes means to detach itself from the rotor assembly without manual effort, e.g. using a sensor and feedback system to establish when the device should be detached from the rotor assembly, or no more manual effort than is required to activate a command, prompt or control means such as pressing a ‘release’ button on a control panel to release it from the rotor assembly.

Ideally, the locating and securing means comprising a transport means.

Ideally, the transport means is for transporting the extraction device to and from the impact crusher.

Ideally, the transport means is for transporting the extraction device between the various in use positions of the extraction device in terms of being mounted on the one or more circumferential mounts of the rotor assembly.

Ideally, the transport means comprising at least one handle, most preferably, at least two handles.

Ideally, the transport means and the extraction device removal means comprising the same handle or handles.

Advantageously, by having the transport means and the extraction device removal means comprising the same manually operated handle provides an ergonomic, space saving design for an extraction device. This helps to keep the design of the extraction device as minimal as possible to save on materials and manufacturing costs in production of the extraction device.

Ideally, the locating and securing means comprises adaptions to provide extra resistance against the extraction force exerted by the extraction device.

Ideally, the blow bar engagement means comprises adaptions to reinforce the structural integrity of the extraction device.

Ideally, the blow bar engagement means comprises adaptions to reinforce the structural integrity of the extraction device provide extra resistance against the extraction force exerted by the extraction device.

Ideally, both the locating and securing means and the blow bar engagement means comprise adaptions to reinforce the structural integrity of the extraction device and provide greater resistance against the extraction force exerted by the extraction device.

By adaptions we mean any adaption that provides reinforcement to the structural integrity of the material used to make the extraction device. If made from metal this could include a fold in the metal to create a flange, shoulder or any other suitable feature such as gussets that increases the structural integrity of the metal by imparting strength and stiffness to (or hardening a) metal by enacting tension and compression within the material.

Ideally, the locating and securing means being adapted for receiving the blow bar engagement means.

Ideally, the locating and securing means comprising a linking means, the linking means being adapted for receiving the blow bar engagement means.

Preferably, the linking means projects from at or about the one or more anchors and is adapted at a location distal from the anchors to receive at least part of the blow bar engagement means.

Ideally, the linking means comprising a means for linking the locating and securing means to the blow bar engagement means.

Ideally, the linking means comprising a linking plate.

Ideally, the linking means comprising a linking plate that projects from the one or more anchors.

Ideally, the linking plate comprising one or more apertures.

Ideally, the linking plate comprising a plurality of apertures.

Preferably, the blow bar engagement means comprising a housing.

Ideally, the blow bar engagement means comprising a face plate.

Preferably, the blow bar engagement means comprising a blow bar engagement member, ideally, the blow bar engagement member being disposed within the housing.

Ideally, the blow bar engagement means comprises an actuating means for moving the blow bar engagement member, most preferably, for moving the blow bar engagement member relative to the housing.

Ideally, the face plate comprising apertures.

Ideally, the linking means, most preferably the linking plate, comprising at least one blow bar engagement member aperture.

Ideally, the blow bar engagement member aperture is sized to receive the blow bar engagement member therethrough.

Ideally, the linking plate comprising at least one blow bar engagement member aperture and at least one other aperture.

Ideally, the at least one blow bar engagement member aperture is equal to or slightly larger in perimeter to the perimeter of the at least one blow bar engagement member and/or housing.

Ideally, the at least one blow bar engagement member aperture being of sufficient perimeter for allowing the at least one blow bar engagement member to penetrate the blow bar engagement member aperture.

Ideally, the at least one blow bar engagement member aperture being of sufficient perimeter for allowing the at least one blow bar engagement member to penetrate the blow bar engagement member aperture in use.

Ideally, the at least one other aperture comprising at least one fastening aperture.

Ideally, the at least one other aperture comprises a plurality of fastening apertures.

Ideally, the fastening apertures are for receiving fastening means to fasten the housing to the locating and securing means.

Preferably, the housing of the blow bar extraction means is fastened to the locating and securing means.

By fastening means we mean a screw, nut and bolt combination, rivet, weld, or any other suitable means for coupling the various components of the extraction device together.

Ideally, the fastening apertures are for receiving fastening means for mechanically coupling the linking means to the housing via fasteners being inserted through the respective fastening holes of the locating and securing means and the blow bar engagement means.

Ideally, the linking plate comprising at least one fastening aperture.

Ideally, the linking plate comprising a plurality of fastening apertures.

Ideally, the face plate of the housing comprising apertures.

Ideally, the face plate and the linking plate are aligned so that their respective corresponding apertures are in alignment.

Ideally, the face plate and the linking plate are aligned so that their respective corresponding apertures are in alignment for allowing the at least one blow bar engagement member move through the blow bar engagement member aperture in use.

Ideally, the face plate and the linking plate are aligned so that their respective corresponding apertures are in alignment for allowing fastening means to be inserted into the fastening apertures.

Ideally, the face plate and the linking plate are aligned so that their respective corresponding apertures are in alignment for allowing fastening means to be inserted into the fastening apertures for fastening the blow bar engagement means to the locating and securing means.

Ideally, the face plate and the linking plate are aligned so that their respective corresponding apertures are in alignment for allowing fastening means to be inserted into the fastening apertures for fastening the blow bar engagement means to the locating and securing means to form the extraction device.

Ideally the blow bar engagement means is coupleable to the locating and securing means.

Ideally the blow bar engagement means is mechanically coupleable to the locating and securing means.

Ideally the blow bar engagement means is detachably coupleable to the locating and securing means.

Ideally the blow bar engagement means is coupleable to the locating and securing means via fastening means.

Ideally the blow bar engagement means is coupleable to the locating and securing means via fastening means being inserted into the aligned fastening apertures in the face plate and the linking plate.

Ideally, the face plate comprising apertures that correspond to the apertures of the linking plate.

By fastening means we mean a nut and bolt, screw, rivet or weld or any other form of fastener suitable for coupling the face plate of the blow bar engagement means to the linking plate of the location and securing means.

Ideally, the fastening means mechanically couple the linking means to the housing to form the extraction device.

Ideally, the blow bar engagement means comprising a housing.

Ideally, the housing extends from the face plate of the blow bar engagement means.

Ideally, the housing houses the blow bar engagement member.

Ideally, the housing comprising a cavity for housing the blow bar engagement member.

Ideally, the blow bar engagement member is movable between an at rest position and an extended position.

By at rest position we mean the position the blow bar engagement member is when retracted within the housing of the extraction device.

By extended position we mean a position wherein the blow bar engagement member projects from the housing.

Ideally, the housing comprising a cavity for housing the blow bar engagement member in the at rest position.

Ideally, the housing corresponds in shape and dimension to the blowbar engagement member.

Ideally, the cavity of the housing corresponds in shape and dimension to the blowbar engagement means.

Ideally, the perimeter of the cavity of the housing corresponds in shape and dimension to the perimeter of the blow bar engagement member.

Ideally, the cross-sectional perimeter of the cavity of the blow bar engagement member corresponds in shape and dimension to the cross-sectional perimeter of the blow bar engagement member.

Ideally, the housing comprising a cavity for housing the blow bar engagement member when the blow bar engagement member is in the at rest position.

Ideally, the housing houses the actuating means.

Ideally, the housing houses the actuating means on the exterior of the housing means.

Ideally, the actuating means are operably mountable on the housing.

Ideally, the actuating means are mounted on the housing

Ideally, the actuating means are mountable on the exterior of the housing.

Ideally, the blow bar engagement member forcibly engages the blow bar for extracting it from its in-use position on the rotor assembly via mechanical force.

Ideally, the blow bar engagement member is movable between at least two positions.

Ideally, the blow bar engagement member is movable between two positions for forcibly engaging the blow bar to move it out of its in-use position on the rotor assembly via mechanical force.

Ideally, the blow bar engagement member is movable between an at rest position and an extended position for forcibly engaging the blow bar to move it out of its in-use position on the rotor assembly via mechanical force.

Ideally, the blow bar engagement member is located in the cavity of the housing.

Ideally, the blow bar engagement member is located in the housing in its at rest position.

Ideally, the blow bar engagement member is located in the cavity of the housing in its at rest position.

Ideally, the blow bar engagement member moves from its at rest position within the housing to its extended position for engaging the blow bar.

Ideally, the blow bar engagement member displaces the blow bar from a rotor assembly in any direction.

Ideally, the blow bar engagement member displaces the blow bar from a rotor assembly in one direction.

Ideally, the blow bar engagement member displaces a blow bar from a rotor assembly in any direction along the longitudinal axis of the blow bar.

Ideally, the blow bar engagement member displaces a blow bar from a rotor assembly in either direction along the longitudinal axis of the blow bar.

Advantageously, during the transition from the at rest position to the extended position the leading face of the blow bar engagement member engages an end of a blow bar and forcibly moves it from its mounted position on the rotor assembly along the longitudinal axis of the blow bar.

Advantageously, by retracting the blow bar engagement member from its extended position back to its at rest position in the housing, the blow bar engagement member can repeat the ejection cycle to dislodge the blow bar from the rotor assembly, or make reposition or transport of the extraction device easier for an operator.

Ideally, the blow bar engagement member is a hydraulic piston rod.

Ideally, the blow bar engagement member is made from metal.

Ideally, the blow bar engagement member is made from a composite material.

Ideally the blow bar engagement means comprises actuating means.

Ideally, the actuating means move the blow bar engagement member between its at rest position and its extended position.

Ideally, the actuating means mechanically actuates the blow bar engagement member.

Ideally, the actuating means comprising ejection means for moving the blow bar from its at rest position into its extended position.

Ideally the actuating means comprising retraction means for moving the blow bar from its extended state to its at rest state.

Advantageously, the ejecting means ejects the blow bar engagement member from the housing from its at rest position to its extended position. In doing so it causes the leading face of the blow bar engagement means to engage an end face of a blow bar in order to forcibly move it out and away from its in-use position, relative to a rotor assembly.

Ideally, the actuating means comprises retraction means.

Ideally, the actuating means comprises retraction means for retracting the blow bar engagement means from its extended state.

Advantageously, retracting the blow bar extraction member from its extended position back to its at rest position facilitates repeat ejections to remove the blow bar from the rotor assembly as required. Furthermore, when the blow bar engagement member is in its at rest state the extraction device can be more easily removed from and attached to the rotor assembly.

Further advantageously, having the blow bar engagement means in its retracted state makes the extraction device easier to transport and store without fear of the extraction device, specifically the blow bar engagement member, becoming damaged or broken.

Ideally, actuating means comprises a hydraulic actuating system.

Ideally, the actuating means comprises a hydraulic pump.

Ideally, the actuating means comprises at least one hydraulic hose.

Ideally, the actuating means comprises at least one hydraulic hose for transferring hydraulic fluid to operate the blow bar engagement means.

Ideally, the at least one hydraulic hose being operably couplable to the housing.

Ideally, the at least one hydraulic hose being connected to and/or being in fluid communication with the hydraulic pump.

Ideally, the at least one hydraulic hose operably connecting the hydraulic pump to the blow bar engagement member.

Ideally, the actuating means comprises a quick-release mechanism for quickly releasing or attaching the at least one hydraulic hose to the extraction device/blow bar engagement means/housing and/or the hydraulic pump, an auxiliary hydraulic circuit or an hydraulic circuit of an impact crusher.

Advantageously, this reduces initial set-up time and deconstruction time.

Ideally, the actuating means comprises a hydraulic circuit.

In one embodiment, the actuating means comprises a closed loop hydraulic actuating system.

In another embodiment, the actuating means comprises an open loop hydraulic actuating system.

In another embodiment, the actuating means comprises an electronic actuating system.

In another embodiment, the actuating means comprises a pneumatic actuating system.

Ideally, the actuating means actuates the blow bar engagement member by one of, or any combination of hydraulic, electronic or pneumatic actuating systems.

Ideally, the actuating means comprising a hydraulic piston.

Ideally, the extraction device is formed at least partially from metal.

Ideally, the extraction device is formed at least partially from steel.

Ideally, the extraction device is formed at least partially from a composite material.

Ideally, the extraction device comprising a control means.

Ideally, the control means being operable to control the actuating means.

Ideally, the control means comprising at least one lever or switch.

Ideally, the control means comprises at least one lever for controlling movement of hydraulic fluid within the hydraulic circuit.

Ideally, the control means comprising at least two levers for controlling movement of hydraulic fluid within the hydraulic circuit.

Ideally, the control means can be operated to extend the blow bar engagement member.

Ideally, the control means can be operated to retract the blow bar engagement member.

In one embodiment, the control means comprising a user interface, a memory storage device and/or a central processing unit.

Ideally, the control means being electrically powered.

Accordingly, the present invention provides an impact crusher comprising a rotor assembly, the rotor assembly comprising at least one blow bar, the impact crusher further comprising a means for operating an extraction device for extracting a blow bar from the rotor assembly.

Ideally, the means for operating an extraction device comprising a means for operably connecting the impact crusher to an extraction device.

Ideally, the means for operably connecting the impact crusher to an extraction device comprising at least one input/output port.

Ideally, the means for operably connecting the impact crusher to an extraction device comprising at least two input/output ports.

Ideally, the means for operating an extraction device comprising a control means for operating an extraction device.

Advantageously, an extraction device can be operated from the control means of the impact crusher and a separate control means is not required.

Ideally, the means for operating an extraction device comprising an actuating means.

Ideally, the means for operating an extraction device comprising a hydraulic pump.

Ideally, the actuating means comprising a hydraulic pump.

Ideally, the hydraulic pump is operably connectable to an extraction device.

Ideally, the means for operating an extraction device comprising at least one hydraulic hose.

Ideally, the at least one hydraulic hose being connected to the means for operably connecting the impact crusher to an extraction device.

Ideally, the at least one hydraulic hose being connected to the at least one input/output port.

Ideally, the means for operating an extraction device comprising a first hydraulic hose and a second hydraulic hose.

Ideally, the first hydraulic hose being connected to one input/output port and the second hydraulic hose being connected to another input/output port.

In one embodiment, the impact crusher comprising an extraction device.

Ideally, the extraction device comprising a means for operably connecting the extraction device to an actuating means.

Ideally, the extraction device comprising at least one input/output port for operably connecting the extraction device to an actuating means.

Ideally, the extraction device being operably connected to the actuating means.

Ideally, the extraction device being operably connected to the hydraulic pump.

Ideally, the extraction device being operably connected to the at least one hydraulic hose.

Ideally, the hydraulic pump, the at least one hydraulic hose and the extraction device forming a hydraulic circuit, most preferably, a closed hydraulic circuit.

Ideally, the extraction device comprising at least one input/output port.

Ideally, the at least one hydraulic hose, the at least one input/output port of the means for operating an extraction device and/or the at least one input/output port of the extraction device comprising a quick-release mechanism.

Ideally, the at least one hydraulic hose is connected to the at least one input/output port of the extraction device, most preferably, via the quick release mechanism.

Ideally, the extraction device comprising locating and securing means for locating and securing the extraction device on an impact crusher.

Ideally, the extraction device comprising a blow bar engagement means movably mountable on the locating and securing means so that the blow bar engagement means can contact the blow bar for forcibly extracting the at least one blow bar out of the rotor assembly.

Ideally, the extraction device comprising locating and securing means for locating and securing the extraction device on the impact crusher.

Ideally, the extraction device comprising a blow bar engagement means movably mountable on the locating and securing means so that the blow bar engagement means is capable of contacting the at least one blow bar for forcibly extracting the blow bar out of the rotor assembly.

Ideally, the rotor assembly comprising means for coupling at least one blow bar on an outer surface of the rotor assembly so that the blow bar extends parallel to and radially spaced from the longitudinal axis of the rotor assembly.

Ideally, the rotor assembly comprising means for coupling a plurality of blow bars on an outer surface of the rotor assembly so that the blow bar extends parallel to and radially spaced from the longitudinal axis of the rotor assembly.

Ideally, the means for coupling are distributed along the longitudinal axis ofthe rotor assembly.

Ideally, the means for coupling are spaced apart angularly around the longitudinal axis of the rotor assembly.

Ideally, the means for coupling are spaced apart angularly around the longitudinal axis of the rotor assembly in a plane perpendicular to the longitudinal axis.

Ideally, the means for coupling are equi-spaced apart angularly around the longitudinal axis of the rotor assembly in a plane perpendicular to the longitudinal axis.

Ideally, the means for coupling are distributed circumferentially around the rotor assembly.

Ideally, the means for coupling are equi-spaced apart angularly circumferentially around the rotor assembly.

Ideally, the means for coupling comprises a plurality of radially extending mounts arranged perpendicular to the longitudinal axis of the rotor assembly.

Ideally, the means for coupling comprises a plurality of radially extending mounts spaced apart about the longitudinal axis of the rotor assembly.

Ideally, the means for coupling comprises a plurality of radially extending mounts arranged along the longitudinal axis of the rotor assembly.

Ideally, the means for coupling comprises a plurality of radially extending mounts arranged about and located along the longitudinal axis of the rotor assembly.

Ideally, the means for coupling comprises a plurality of radially extending mounts axially aligned along the longitudinal axis of the rotor assembly.

Ideally, the rotor assembly comprises an open-mouth recess between each angularly spaced apart co-planar coupling means.

Ideally, the alignment of the open mouth recess/radially extending mounts of the rotor assembly comprises a longitudinal channel therebetween.

Ideally, the rotor assembly comprising one or more open-mouthed recesses between each angularly spaced apart circumferential coupling means in the plane perpendicular to the longitudinal axis.

Ideally the open mouthed recesses face radially outward from the longitudinal axis of the rotor assembly.

Ideally, a plurality of open mouthed recesses align axially along the longitudinal axis of the rotor assembly.

Ideally, the plurality of open mouthed recesses align axially along the longitudinal axis of the rotor assembly between circumferential coupling means to form a recessed channel.

Ideally, the rotor assembly comprises a plurality of recessed channels.

Ideally, the plurality of recessed channels are angularly spaced around the longitudinal axis of the rotor assembly.

Ideally, the coupling means comprises a blow bar backing bar.

Ideally, the radially extending mounts of the longitudinally aligned coupling means is bridged by a blow bar backing bar.

Ideally, the blow bar backing bar extends parallel to and radially spaced from the longitudinal axis of the rotor assembly.

Ideally, the blow bar backing bar extends parallel to and radially spaced from the longitudinal axis of the rotor assembly being attached to each of the radially extending mounts in a row of coupling means.

Ideally, the blow bar backing bar extends parallel to and radially spaced from the longitudinal axis of the rotor assembly bridging the radially extending mounts in a row of coupling means.

Ideally, the recessed channel is of suitable size for receiving the blow bar.

Ideally, the recessed channel is of suitable size for receiving the blow bar as well as any further coupling apparatus required for coupling the blow bar to the coupling means.

Accordingly, the present invention provides a non-manual extraction device for extracting a blow bar from a rotor assembly in an impact crusher, the extraction device comprising a blow bar engaging means capable of contacting a blow bar for forcibly extracting the blow bar out of the rotor assembly.

By “non-manual” we mean the force acting on the blow bar when the extraction device is operated is not a force resulting from manual input, e.g., by swinging a sledgehammer. It is not required for a worker to use their own strength to dislodge the blow bar from the rotor assembly, and removal of the blow bar is at least assisted by operation of the extraction device.

Ideally, the extraction device comprises a locating and securing means for locating and securing the extraction device on an impact crusher.

Accordingly, the present invention provides an impact crusher comprising a rotor assembly, the rotor assembly comprising at least one blow bar, the impact crusher further comprising a non-manual extraction device for extracting a blow bar from a rotor assembly in an impact crusher, the extraction device comprising a blow bar engaging means capable of contacting a blow bar for forcibly extracting the blow bar out of the rotor assembly.

Accordingly, the present invention provides a kit of parts comprising an extraction device for extracting a blow bar from a rotor assembly and a means for operating an extraction device.

Ideally, the means for operating an extraction device comprising at least one hydraulic hose.

Ideally, the means for operating the extraction device comprising a control means.

Ideally, the means for operating the extraction device comprising an actuating means.

Ideally, the actuating means comprising a hydraulic pump.

In one embodiment, the kit of parts comprising an impact crusher.

Ideally, the kit of parts comprising a rotor assembly.

Accordingly, the present invention provides a method for extracting a blow bar from a rotor assembly of an impact crusher, the method comprising placing a blow bar extraction device on an impact crusher so that the blow bar extraction device is operably engageable with the blow bar for forcibly removing the blow bar from the impact crusher.

Ideally, the method comprising the steps of fitting the blow bar extraction device on the impact crusher.

Ideally, the method comprising fitting the blow bar extraction device on the impact crusher via the locating and securing means.

Ideally, the method comprising fitting the blow bar extraction device on a rotor assembly.

Ideally, the method comprising fitting the blow bar extraction device on a rotor assembly via the locating and securing means.

Ideally, the method comprising fitting the blow bar extraction device on a radially extending circumferential mount of a rotor assembly.

Ideally, the method comprising fitting the blow bar extraction device on a radially extending circumferential mount of a rotor assembly via the locating and securing means.

Ideally, the method comprising fitting the blow bar extraction device on a radially extending circumferential mount of a rotor assembly via the locating and securing means.

Ideally, the method comprising aligning the blow bar extraction device with a blow bar.

Ideally, the method comprising aligning the blow bar engagement member with a blow bar.

Ideally, the method comprising connecting at least one hydraulic hose to the blow bar extraction device.

Ideally, the method comprising connecting two hydraulic hoses to the blow bar extraction device.

Ideally, the method comprising connecting two hydraulic hoses to the blow bar extraction device using the quick-release mechanism.

Ideally, the method comprising connecting the at least one hydraulic hose to a hydraulic pump forming a hydraulic circuit.

Ideally, the method comprising operating the control means.

Ideally, the method comprising activating the actuating means to extend the blow bar extraction member.

Ideally, the method comprising activating the actuating means to retract the blow bar extraction member.

Ideally, the method comprising removing the blow bar extraction device from the gripping the at least one handle and pulling the blow bar extraction device away from the rotor assembly.

Ideally, the method comprising fitting the blow bar extraction device to an adjacent radially extending circumferential mount of a rotor assembly.

Ideally, the method comprising repeating previous steps to fully remove a blow bar from a rotor assembly.

The invention will now be described with reference to the accompanying drawings which shows by way of example only one embodiment of an apparatus in accordance with the invention.

Figure 1 shows a front perspective view of an extraction device according to the invention;

Figure 2 shows a top plan view of the extraction device in Figure 1;

Figure 3 shows an alternative perspective view of the extraction device shown in Figure 1;

Figure 4 shows a perspective view of the extraction device in situ, i.e. mounted on a rotor assembly immediately prior to extraction with the blow bar engagement member in the rest position;

Figure 5 shows an exploded perspective view of the extraction device in Figure 4;

Figure 6 shows a perspective view of an impact crusher chamber in the open/repair position with the extraction device mounted on the rotor assembly within the impact crusher in situ;

Figure 7 shows an exploded perspective view of the extraction device of Figure 6;

Figure 8 shows a partial top perspective view of the extraction device mounted in situ on a rotor assembly within an impact crusher;

Figure 9 shows an exploded, rotated top perspective view of the extraction device mounted in Figure 8.

Figure 10 shows an expanded perspective view of an impact crusher according to the invention in the open/repair position;

Figure 11 shows a side elevation view of the impact crusher of Figure 10 in the operational position;

Figure 12 is a detailed view of the control arrangement of the impact crusher in Figure 10.

Referring to the drawings and initially to Figures 1 to 3, there is shown an extraction device generally by the reference numeral 1. The extraction device 1 has a locating and securing arrangement 2 for locating and securing the extraction device on an impact crusher, and a blow bar engagement arrangement 3 movably mountable on the locating and securing arrangement 2. The blow bar engagement arrangement 3 can contact a blow bar for forcibly extracting the blow bar out of a rotor assembly of an impact crusher. The extraction device 1 can be movably mounted at a plurality of longitudinally spaced positions along the circumference of a rotor assembly, enabling it to be moved and repositioned such that the blow bar engagement arrangement 3 is in alignment with the blow bar. The locating and securing arrangement 2 releasably couples the extraction device 1 to a rotor assembly, in particular, orthogonal to a portion of the radially extending circumferential mounts of a rotor assembly proximal to the blow bar backing bar and in a manner to align to the blow bar engagement arrangement 3 with the blow bar at the point of impact. The locating and securing arrangement 2 is shaped to correspond with and engage with the radially extending circumferential mounts of a rotor assembly (as shown in Figures 4 to 10).

The locating and securing arrangement 2 has a captivating arrangement 4 for securing the extraction device to a radially extending circumferential mount of a rotor assembly, thereby mechanically securing the extraction device to a rotor assembly. The captivating arrangement 4 has two spaced apart anchors 5a, 5b, the anchors being Cshaped fixed jaws. The captivating arrangement 4 is releasable so the extraction device 1 can be removed and repositioned to a second position to perform another extraction cycle at a different location along the rotor assembly continuing the blow bar extraction exercise following completion of an extraction cycle in a first position. The extraction device 1 further has two handles 6a, 6b for transporting the extraction device 1 and for manually removing the extraction device 1 from being mounted on a rotor assembly.

The extraction device 1 has a linking plate 7 for linking the locating and securing arrangement 2 with the blow bar engagement arrangement 3. The linking plate 7 extends from the two anchors 5a, 5b and one of the handles 6b extends from the linking plate 7. The linking plate 7 further has two fastening apertures 8a, 8b for fastening the linking plate to the blow bar engagement arrangement 3. The linking plate 7 further has a blow bar engagement member aperture 9 being sized to receive a blow bar engagement member.

The blow bar engagement arrangement 3 has a housing 10, a face plate 11, a blow bar engagement member 12, and an actuating arrangement 13. The perimeter of the blow bar engagement member aperture 9 is sized to receive the blow bar engagement member 12 and in use the blow bar engagement member 12 travels through the blow bar engagement member aperture 9. The face plate 11 has two apertures that correspond to the fastening apertures 8a, 8b of the linking plate. The face plate 11 is fastened to the linking plate via a nut and bolt in each of the fastening apertures 8a, 8b. The linking plate 7 has two flanges 14a, 14b that reinforce the linking plate 7 and locate the face plate 11 against the linking plate 7 and such that the apertures of the face plate 11 are in alignment with the fastening apertures 8 of the linking plate 7. The housing 10 extends perpendicularly from the face plate 11 of the blow bar engagement arrangement 3 and houses the blow bar engagement member 12 within a cavity (not shown). The perimeter of the cavity of the housing 11 corresponds in shape and dimension to the perimeter of the blow bar engagement member 12. The actuating arrangement 13 has two input/output ports 30a, 30b arranged on the outside of the housing 10 that are arranged with a quick-release mechanism to arrange fast attachment to, or release from, hydraulic hoses (as shown in Figure 10).

The blow bar engagement member 12 is operable to forcibly engage a blow bar for extracting it from its in-use position on the rotor assembly via mechanical force, the blow bar engagement member 12 being movable between a rest position, as shown in Figures 1 to 3, to an extended position (not shown). In the rest position the blow bar extraction member 12 is situated almost entirely within the housing 11. In the extended position the blow bar engagement member 12 is extended out from the housing 11. The blow bar engagement member 12 is a hydraulic piston rod. The actuating arrangement 13 is operable to move the blow bar engagement member 12 between its at rest position and its extended position. The actuating arrangement 13 is a hydraulic actuating system that is operable to extend and retract the blow bar engagement member 12.

Figures 4 and 5 illustrates a rotor assembly 20 and a blow bar extraction device 1. The rotor assembly 20 has four blow bars 21a, 21b, 21c and an arrangement 22 for coupling each of the blow bars 21a, 21b, 21c on outer surface of the rotor assembly 20 so that the blow bars 21a, 21b, 21c extends parallel to and radially spaced from the longitudinal axis of the rotor assembly 20. The arrangement for 22 for coupling each of the blow bars 21a, 21b,

21c distributed along, spaced apart angularly, the longitudinal axis of the rotor assembly and in a plane perpendicular to the longitudinal axis. The arrangement 22 for coupling each of the blow bars 21a, 21b, 21c are equi-spaced apart angularly around the longitudinal axis of the rotor assembly 20 in a plane perpendicular to the longitudinal axis, and are distributed circumferentially around the rotor assembly 20.

The arrangement 22 for coupling has four of radially extending mounts 23a, 23b, 23c, 23d arranged spaced apart and perpendicular to the longitudinal axis of the rotor assembly 20. The radially extending mounts 23a, 23b, 23c, 23d are arranged along and are located about the longitudinal axis of the rotor assembly 20. The radially extending mounts 23a, 23b, 23c, 23d are axially aligned along the longitudinal axis of the rotor assembly 20. The rotor assembly 20 has four open-mouth recesses 24 between each angularly spaced apart coplanar coupling arrangement 22, forming a longitudinal channel. The open-mouth recesses are in the plane perpendicular to the longitudinal axis of the rotor assembly 20 and face radially outward from the longitudinal axis of the rotor assembly 20. The four open-mouth recesses 24 are aligned axially along the longitudinal axis of the rotor assembly 20. The four open mouthed recesses 24 align axially along the longitudinal axis of the rotor assembly 20 between circumferential coupling arrangements 22 to form a recessed channel being sized to receive a blow bar 21a, 21b, 21c. The coupling arrangement 22 further has a blow bar backing bar 26 which bridges the radially extending mounts 23a, 23b, 23c, 23d of the longitudinally aligned coupling arrangement 22. The blow bar backing bars 26 extend parallel to and radially spaced from the longitudinal axis of the rotor assembly 22. Figures 6 to 9 further illustrate the rotor assembly 20 being situated within an impact crusher 30.

Figures 10 and 11 illustrate an impact crusher 40 according to the invention having a rotor assembly 20 and an extraction device 1. The impact crusher 40 has a control arrangement 41 for controlling the extraction device 1. The control arrangement 41 has six control levers 42a, 42b, 42c, 42d, 42e, 42f for controlling the impact crusher and actuation of the extraction device. The impact crusher 40 further has a hydraulic pump (not shown), two input/output ports 43a, 43b and two hydraulic hoses 44a, 44b connected to the input/output ports via a quick-release mechanism and extending therefrom. The hydraulic hoses 44a, 44b are operably connected to the input/output ports 30a, 30b of the extraction device 1. Figure 11 illustrates a detailed view of the control arrangement 41. The impact crusher 40 has a main conveyor 45 that can be raised or lowered by operating the first lever 42a of the control arrangement 41. The impact crusher 40 further has a top lid 46 that can be opened or closed by operating the second lever 42b of the control arrangement 41. The impact crusher 40 further has an apron 47 which can be moved heightwise by operating the third lever 42c of the control arrangement 41, and laterally by operating the fourth lever 42d of the control arrangement 41. The impact crusher can be opened to expose the rotor arrangement 20, or closed, by operating the fifth lever 42e of the control arrangement 41. The blow bar engagement member 12 of the extraction device 1 can be operated to extend or retract via the sixth lever 42f of the control arrangement.

In use, a blow bar 21a, 21b, 21c can be removed from the rotor assembly 20 by switching off the impact crusher 40 and opening the impact crusher by operating the fifth lever 42e of the control arrangement 41. The extraction device 1 is then mounted onto a radially extending circumferential mount of a rotor assembly 20 in a transverse or orthogonal fashion, as shown in Figures 5 to 9. The extraction device 1 is mounted by gripping the extraction device 1 by the handles 6a, 6b, raising it and setting it on a radially extending circumferential mount such that the two anchors 5a, 5b of the locating and securing arrangement 2 are located at either side of the radially extending circumferential mount, and such that the blow bar engagement member 12 is in alignment with the blow bar 21a, 21b, 21c. The actuating arrangement 13 is then operated via the sixth lever 42f of the control arrangement 41 causing the blow bar engagement member 12 to move from the rest position to the extended position thereby forcing the blow bar 21a, 21b, 21c out of its in-use position. The actuating arrangement 13 is then again operated to return the blow bar engagement member 12 to its rest position. The blow bar extraction device 1 is then repositioned to the adjacent radially extending circumferential mount and the cycle is repeated to further force the blow bar along, and eventually out of, the rotor assembly 20. The extraction device 1 absorbs the impact force exerted by the blow bar engagement member 12. In particular, the locating and securing arrangement 2, the anchors 5a, 5b, and the radially extending circumferential mounts of the rotor assembly 20 absorb the impact force. Once all replacement or repairs are complete the impact crusher 40 can be closed by operating the fifth lever 42e of the control arrangement 41.

In relation to the detailed description of the different embodiments and aspects of the invention, it will be understood that one or more technical features of one embodiment or aspect can be used in combination with one or more technical features of any other embodiment or aspect where the transferred use of the one or more technical features would be immediately apparent to a person of ordinary skill in the art to carry out a similar function in a similar way on the other embodiment or aspect.

In the preceding discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of the said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The features disclosed in the foregoing description or the following drawings, expressed in their specific forms or in terms of a means for performing a disclosed function, or a method or a process of attaining the disclosed result, as appropriate, may separately, or in any combination of such features be utilised for realising the invention in diverse forms thereof as defined in the appended claims.

Claims (25)

1. A non-manual extraction device for extracting a blow bar from a rotor assembly in an impact crusher, the extraction device comprising a blow bar engaging means capable of contacting a blow bar for forcibly extracting the blow bar out of the rotor assembly.

2. A non-manual extraction device as claimed in claim 1 wherein the extraction device is movably mountable at a plurality of longitudinally spaced positions along the circumference of a rotor assembly so that the blow bar engagement means is in alignment with the blow bar at the point of impact at each of these positions.

3. A non-manual extraction device as claimed in claims 1 or 2 comprising a locating and securing means for locating and securing the extraction device on an impact crusher.

4. A non-manual extraction device as claimed in claim 3 wherein the locating and securing means is adapted to releasably couple the extraction device to a rotor assembly.

5. A non-manual extraction device as claimed in claims 3 or 4 wherein at least part of the locating and securing means corresponds in shape to one or more of the radially extending circumferential mounts of a rotor assembly and wherein the locating and securing means couples to a rotor assembly by engaging one or more radially extending circumferential mounts of the rotor assembly via friction fit, snap fit, interference fit or any other suitable type of fit.

6. A non-manual extraction device as claimed in any one of claims 3 to 5 wherein the locating and securing means comprises captivating means and wherein the captivating means secures the extraction device to the rotor assembly.

7. A non-manual extraction device as claimed in claim 6 wherein the captivating means comprises additional locking means such as some sort of lock, or latch, or pin, or other mechanical coupling means.

8. A non-manual extraction device as claimed in any one of claims 3 to 7 wherein the locating and securing means comprises at least one anchor for engaging the one or more radially extending circumferential mounts.

9. A non-manual extraction device as claimed in claim 8 wherein the locating and securing means comprises pair of spaced apart anchors for engaging the one or more radially extending circumferential mounts.

10. A non-manual extraction device as claimed in any one of claims 3 to 9 wherein the locating and securing means comprises a linking means, the linking means being adapted for receiving the blow bar engagement means.

11. A non-manual extraction device as claimed in claim 10 when dependent on claim 8 wherein the linking means projects from at or about the one or more anchors and is adapted at a location distal from the anchors to receive at least part of the blow bar engagement means.

12. A non-manual extraction device as claimed in any preceding claim comprising a housing, a face plate, a blow bar engagement member disposed within the housing, and/or an actuating means for moving the blow bar engagement member relative to the housing.

13. A non-manual extraction device as claimed in claim 12 when dependent on claim 11 wherein the linking means comprises at least one blow bar engagement member aperture sized to receive the blow bar engagement member therethrough.

14. A non-manual extraction device as claimed in claim 12 or 13 wherein the blow bar engagement member is movable between an at rest position, where the blow bar engagement member is retracted within the housing of the extraction device, and an extended position where the blow bar engagement member projects form the housing.

15. A non-manual extraction device as claimed in any one of claims 12 to 14 wherein the actuating means are operably mounted on the housing.

16. A non-manual extraction device as claimed in any one of claims 12 to 15 wherein the actuating means is a hydraulic actuating system.

17. A non-manual extraction device as claimed in claim 16 wherein the hydraulic actuating system comprises a hydraulic hose operably couplable to the housing and wherein the actuating means comprises a quick-release mechanism for quickly releasing or attaching the hydraulic hose to the housing.

18. A non-manual extraction device as claimed in any preceding claim comprising a control means to operate the device.

19. A non-manual extraction device as claimed in claim 18 when dependent on claim any one of claims 12 to 17 wherein the control means is operable to control the actuating means.

20. A non-manual extraction device as claimed in any preceding claim comprising an extraction device removal means for removing the extraction device from being mounted on a rotor assembly.

21. A non-manual extraction device as claimed in claim 20 wherein the extraction device removal means comprises at least one manually operated handle.

22. A non-manual extraction device as claimed in claim 21 wherein the extraction device removal means comprises two spaced manually operated apart handles.

23. A non-manual extraction device as claimed in any preceding claim comprising adaptations to provide extra resistance against the extraction force exerted by the extraction device and/or to reinforce the structural integrity of the extraction device.

24. An impact crusher comprising a rotor assembly, the rotor assembly comprising at least one blow bar, the impact crusher further comprising a non-manual extraction device for extracting a blow bar from a rotor assembly in an impact crusher, the extraction device comprising a blow bar engaging means capable of contacting a blow bar for forcibly extracting the blow bar out of the rotor assembly.

25. An impact crusher comprising a rotor assembly, the rotor assembly comprising at least one blow bar, the impact crusher further comprising a means for operating an extraction device for extracting a blow bar from the rotor assembly.