Patent Description:
Jaw crusher units typically comprise a fixed jaw and a movable jaw that together define a crushing zone. A drive mechanism is operative to rock the movable jaw back and forth in order to crush material within this zone. The crushing zone is generally convergent towards its lower discharge end so that crushable material, fed to an upper and wider end of the zone, is capable of falling downward under gravity whilst being subject to repeated cycles of crushing movement in response to the cyclical motion of the movable jaw. The crushed material is then discharged under gravity through the lower discharge end onto a conveyor belt for onward processing or to a suitable stockpile.

From <CIT> there is known a jaw assembly for a jaw crusher, comprising a jaw stock, a wear plate, and a fastening device in the form of a bolt with a square head at one end and a washer and fastening nut positioned at an end opposite to the one end. The bolt extends between the jaw stock and the wear plate. The fastening device is operative to adopt a clamped configuration where the device provides a clamping force along a fastening axis to clamp the wear plate at the jaw stock, and a released configuration where the fastening device does not prevent the wear plate from being separated from the jaw stock. The fastening device is accessible from a direction that is transverse to that fastening axis, to enable the device to be changed from its clamped configuration to its released configuration.

Due to the forces exerted on the jaws the jaw liners wear over time and are required to be replaced. Current jaw liners have holes on the working surface for receipt of lifting hooks when the jaw liners are to be replaced. These holes add cost and complexity to the process of casting the jaw liners and also reduce the efficiency of the crushing operation.

Current jaw liners also incorporate retention assemblies that are intended to limit lateral movement of the jaw liner relative to the jawstock (frame). The retention assembly comprises internally cast spigots that interface with the rear face of the jaw liners. The lateral retention spigots can and do shear off if a large crushing force is experienced and to repair the casting is expensive and time intensive.

It is an objective of the invention to overcome at least one of the above-referenced problems.

The objective is met by the provision of a jaw assembly for a jaw crusher that comprises a lateral retainer insert that couples the top of the jaw liner with an underside of a retainer plate such as a retainer wedge plate. The insert has a head portion that is accommodated in a recess in the base of the retention plate and an anchor portion that is accommodated in a recess in a rear of the jaw liner. The recesses are not exposed at the front of the jaw liner and thus provide protection for the insert. The retainer insert is also frangible so that when the jaw assembly encounters heavy loads, it breaks allowing the jaw liner to move and avoid structural damage to the fixed Jaw. Additionally, as the head portion of the retainer insert is exposed proud of the top of the jaw liner (See <FIG>), it can function as a lifting attachment when the jaw liner needs to be replaced or rotated.

In a first aspect, the invention provides a jaw assembly of a jaw crusher, comprising:.

In any embodiment, the retainer assembly comprises:.

In an embodiment, the head part of the retainer insert comprises a lifting eye.

In an embodiment, the retainer insert is frangible.

In an embodiment, the retainer insert comprises a bolt having a first end comprising the head part and a second part that is threaded, and a corresponding threaded nut.

In an embodiment, the jaw assembly comprises a first retainer assembly disposed towards each side of the jaw liner and one (or more) second retainer assembly disposed towards a centre of the jaw liner.

In an embodiment, a tolerance defined between the second recess and head part of the second retainer is larger than a tolerance defined between second recess and head part of the first retainer.

In an embodiment, the jaw assembly comprises two first retainer assemblies and two second retainer assemblies disposed at a top of the jaw assembly.

In an embodiment, the first recess extends across part or all of the jaw liner to define an inwardly projecting flange in the top of the jaw liner.

In an embodiment, the or each second recess is formed in the base and a rear of the retention wedge plate.

In an embodiment, the jaw assembly further comprises a second retention plate to clamp the bottom of the jaw liner to the support face, the second retention plate having a top that in use abuts the bottom of the jaw liner.

In an embodiment, the jaw assembly comprises:.

In an embodiment, the first retention plate and/or second retention plate is a retention wedge plate.

In an embodiment, the second recess is disposed in (e.g. comprises an opening formed in) the base and rear of the first retention plate.

In another aspect, the invention provides a jaw of a jaw crusher, comprising a jaw assembly of the invention.

In another aspect, the invention provides a jaw crusher comprising a stationary jaw and a mobile jaw, wherein one of the stationary jaw and a mobile jaw comprise a jaw assembly according to the invention.

Other aspects and preferred embodiments of the invention are defined and described in the other claims set out below.

As used herein, the term "comprise," or variations thereof such as "comprises" or "comprising," are to be read to indicate the inclusion of any recited integer (e.g. a feature, element, characteristic, property, method/process step or limitation) or group of integers (e.g. features, element, characteristics, properties, method/process steps or limitations) but not the exclusion of any other integer or group of integers. Thus, as used herein the term "comprising" is inclusive or openended and does not exclude additional, unrecited integers or method/process steps.

The invention will now be described with reference to specific Examples. These are merely exemplary and for illustrative purposes only: they are not intended to be limiting in any way to the scope of the monopoly claimed or to the invention described. These examples constitute the best mode currently contemplated for practicing the invention.

Referring in particular to <FIG> of the drawings, there is shown a jaw crusher, generally indicated as <NUM>. The jaw crusher <NUM> is of a general type commonly used in material processing operations to crush rocks or other crushable material. Typically, the crusher <NUM> is installed on a material processing apparatus (not shown), which includes other components that co-operate directly or indirectly with the crusher <NUM>, for example conveyor(s), feeder(s), hopper(s) and/or screen(s), all of which may be mounted on a chassis (with wheel(s) and/or track(s)) or other base.

The jaw crusher <NUM> comprises first and second opposed crushing jaws <NUM>, <NUM>, at least one of which is movable with respect to the other to enable the jaws <NUM>, <NUM> to crush material between the jaws <NUM>, <NUM>. In typical embodiments, the first jaw <NUM> is fixed and the second jaw <NUM> is movable towards and away from the first jaw <NUM> in an oscillatory manner.

A drive system is provided for moving the, or each, movable jaw. Typically the drive system comprises a rotatable wheel <NUM> (typically a fly wheel) coupled to an eccentric shaft <NUM>, the shaft <NUM> being coupled to one end of the movable jaw <NUM>. The movable jaw <NUM> is also coupled to a toggle mechanism <NUM>, which typically includes a toggle plate <NUM> and a tensioning rod and spring or ram assembly <NUM>. A motor (not shown) is coupled to the wheel <NUM>, for example by a drive belt (not shown), for the rotation thereof. In use, the motor rotates the wheel <NUM> causing the upper end of the jaw <NUM> to oscillate, while the toggle mechanism <NUM> causes or facilitates oscillatory movement of the lower end of the jaw <NUM>.

Typically, side walls <NUM> are provided beside the jaws <NUM>, <NUM> to form, together with the jaws <NUM>, <NUM>, a crushing chamber. All of the crusher components may be provided on any suitable base (not shown).

Each jaw <NUM>, <NUM> comprises a frame <NUM> (which may be referred to as a jawstock) and a jaw liner <NUM>. Each jaw liner <NUM> has a working (crushing) surface <NUM>, a rear surface <NUM>, a top part <NUM> and a bottom part <NUM>. The respective crushing surfaces oppose one another so that material can be crushed therebetween. The crushing surfaces <NUM> may be fluted, comprising a plurality of parallel ridges <NUM>. Each ridge <NUM> typically extends in a top-to-bottom direction of the jaw liner <NUM>. The jaw liners <NUM> are typically plate-like in form (and may be referred to as jaw plates). The crushing surfaces <NUM> are typically rectangular. Each jaw liner <NUM> is removable from the respective jawstock <NUM> to allow it to be replaced, for example in the event that it becomes overly worn through use.

In the illustrated embodiment, each of the jaw liners <NUM> is removable. In alternative embodiments, only one of the jaw liners may be removable. Alternatively still, one of the crushing surfaces may be integrally formed with the respective jawstock rather than being formed on a jaw liner.

The jaw liners <NUM> are secured in place on the respective jawstock <NUM> by a first (upper) retention wedge plate <NUM> and a second (lower) retention wedge plate <NUM>. The retainer wedge plates <NUM>, <NUM> are shaped and dimensioned to be wedged between a jaw liner <NUM> and frame <NUM> in order to hold the liner in place. To this end, the frame <NUM> may be shaped to define a recess <NUM> adjacent the jaw liner <NUM> (when fitted) into which the locking wedge plate <NUM>, <NUM> may be wedged. The wedge plates are secured to the frame by bolts <NUM> that extend through holes <NUM> in the plates and holes <NUM> in the frame and are locked with locking nuts <NUM>. In the embodiment shown, the first retention wedge plate <NUM> is provided by two retainer wedge plates 25a and 25b vertically symmetrical about the centre.

The rear surface <NUM> of the jaw liner <NUM> includes a first recess <NUM> that extends across a top of the jaw liner and defines an inwardly extending flange <NUM> that forms part of the top part <NUM> of the jaw liner. The flange <NUM> includes four through holes <NUM>, two lateral through holes 42a and two central through holes 42b. Each through hole <NUM> extends from the first recess <NUM> through to the top of the jaw liner.

Referring to <FIG>, one of the retainer wedge plates 25a, 25b is illustrated. The plate has a wedge-shaped base <NUM> including two second recesses 51a and 51b that are formed in a rear <NUM> and base <NUM> of the plate. As illustrated in <FIG>, the recess 51a that in use is located above a centre of the jaw liner <NUM> is larger than the recess 51b that in use is located above a side of the jaw liner.

The jaw assembly of the invention includes a retainer assembly to secure the jaw liner <NUM> relative to the frame <NUM> and limit lateral movement therebetween. This is achieved by providing a retainer insert <NUM> that couples the jaw liner to the retainer wedge plate. The insert is illustrated in <FIG> and comprises a bolt <NUM> with a head part <NUM> at one end and a threaded second end <NUM> and corresponding threaded nut <NUM> which forms the anchor part of the insert. The head part <NUM> includes a lifting eye <NUM>. The bolt has a length enabling it to project through the flange <NUM> forming part of the top of the jaw liner <NUM>. The head part <NUM> is dimensioned to be accommodated within the recesses 51a and 51b, with the tolerance between the head part <NUM> and recess 51a being greater than the tolerance between the head part <NUM> and recess 51b.

<FIG> show the jaw liner with the retainer inserts <NUM> in place. <FIG> illustrates the retainer insert <NUM> projecting through the hole <NUM> in the flange <NUM> with the head part <NUM> located within the second recess <NUM> and the anchor part located within the first recess <NUM>.

<FIG> is a front perspective view of a jaw assembly of the invention in which a front section of the retainer wedge plates 25a, 25b is removed to show the second recesses <NUM> with the head parts <NUM> located in the recesses.

Referring to <FIG>, part of the base of the jaw liner <NUM> is illustrated in more detail. The jaw liner is retained in position by a second (lower) retention wedge plate <NUM> which abuts the base of the jaw liner. The rear base of the jaw liner includes a first recess, and a retention insert <NUM> which is similar to that described previously couples the base of the jaw liner to the wedge plate <NUM> with an anchor part of the insert <NUM> being accommodated in the recess and the head part <NUM> engaging a side <NUM> of the wedge plate <NUM>.

<FIG> illustrate the use of the jaw assembly during removal of the jaw liner. In <FIG>, the two retainer wedge plates 25a, 25b are removed by unscrewing the bolts <NUM> and detaching the plates 25a, 25b to expose the top of the jaw liner <NUM> and the head parts <NUM> of the retainer inserts <NUM> that extend proud above the top of the plate. A lifting eye <NUM> is then attached to each head part <NUM>, and then lifting chains <NUM> are attached to the lifting eye as illustrated in <FIG> allowing the jaw liner to be lifted by a hoist.

The benefits of this invention are the replaceability in case of large failure loads - the retainer insert will fracture saving the expensive cast items. The recess in the wedge plate provides protection to the retainer insert during normal operation where otherwise it could be subjected to material flow and subsequent wear. Further to this, the removable insert can interface with conventional lifting equipment, this allows the jaw liner to be safely lifted and turned or replaced.

Claim 1:
A jaw assembly of a jaw crusher (<NUM>), comprising:
a jaw liner (<NUM>) having a front working face (<NUM>), a rear face (<NUM>), a top (<NUM>), and a bottom (<NUM>);
a frame (<NUM>) forming part of a jaw (<NUM>, <NUM>), the frame having a support face that in use abuts the rear face (<NUM>) of the jaw liner (<NUM>);
a first retention plate (25a, 25b) to clamp the top of the jaw liner to the support face, the first retention plate having a base (<NUM>) that in use abuts the top of the jaw liner; and
a retainer assembly to limit lateral movement of the jaw liner (<NUM>) relative to the frame (<NUM>), the retainer assembly comprising:
a first recess (<NUM>) in an upper part the rear face (<NUM>) of the jaw liner (<NUM>);
a second recess (51a, 51b); and
a removable retainer insert (<NUM>) that extends through the top (<NUM>) of the jaw liner (<NUM>) and comprising a head part (<NUM>) and an anchor part;
characterized in that the second recess (51a, 51b) is disposed in the base (<NUM>) of the first retention plate (25a, 25b); in that the head part (<NUM>) is accommodated within the second recess (51a, 51b); in that the anchor part is accommodated within the first recess (<NUM>).