Patent Description:
An HPGR comprises a pair of rollers which are counter-rotated, and which grind ore fed in the gap between the rollers. The roller surface experiences very large pressures, so it is common for tungsten carbide studs to be provided on the roller surface, protruding radially therefrom.

In typical HPGRs, the roller surface is provided by a hollow cylindrical steel tyre that has a plurality of spaced apertures (or holes) into which high wear material studs (typically made from tungsten carbide) are partially inserted during manufacture of the roller, such that an outer portion of each stud protrudes radially beyond the outer surface of the tyre.

The studs are retained in their respective holes adhesively. However, it is important that an operatively inner or root end of each stud is in direct contact with the material of the tyre forming the inner or blind end of the associated hole. This ensures that a load applied to a stud during operation is transmitted directly from the stud to the tyre and the adhesive serves primarily to retain the stud in the hole. If there is a gap between the root end of the stud and the inner end of the hole then loads applied to the stud are transmitted to the tyre through the adhesive interface between the stud and the tyre. This can result in failure of the adhesive interface and loosening or even falling out of the stud.

Currently, each stud is manually installed in its associated hole. The installation procedure involves the installer introducing an adhesive into a hole in the tyre. After the adhesive is introduced, the installer inserts a stud into the hole. A drill mounted tool is then used to engage the operatively outer end of the stud and urge the stud into the hole and at the same time to rotate the stud. This ensures that the entire surface of the stud located in the hole is coated with adhesive. In addition, it permits air trapped in the hole to escape together with excess adhesive. As mentioned above, it is important that the stud is fully inserted into the hole. One way in which the installation of the stud is checked is by striking the stud, after installation, with a plastic hammer. The sound which is emitted differs when the stud is fully inserted and when it is not fully inserted. Another way in which the insertion of the stud is checked is by checking the extent to which the stud protrudes from the outer surface of the tyre, e.g., using a straight strip. The studs should all protrude from the surface of the tyre by approximately the same distance and if this is not the case it may be necessary to remove the stud and check that it is within specification.

Each roller has a large number of studs, typically of the order of <NUM>,<NUM> (depending on the size of the roller), and accordingly, the installation of the studs is extremely time consuming and is prone to human error. For example, the quantity of adhesive which is applied may vary from hole to hole. In addition, in view of the tedious nature of the job, it is easy for an installer to lose concentration and not install one or more studs properly. It is extremely difficult to check after the installation of the studs whether any have been installed incorrectly.

<CIT> discloses an automatic device for the extraction and installation of the means of fixing the liners in a mill.

<CIT> discloses an apparatus for suspending and guiding at least one tool externally of a grinding mill.

It is an object of an embodiment of this invention to ameliorate this problem or provide a useful alternative.

This summary is provided to introduce a selection of concepts that are further described in the detailed description below.

In this application relative terms are used, such as front, rear, up, down, etc., only for ease of the description and understanding of the embodiments, not by way of limitation. Ordinal numbers (first, second, third, etc.) are assigned arbitrarily herein, and are used to differentiate between parts, and do not indicate a particular order, sequence or importance.

According to a first aspect of the invention there is provided a stud installation machine as set forth in claim <NUM>.

The adhesive dispensing arrangement may include a dispensing head which is insertable into a hole in the tyre and to dispense adhesive onto the surface of the tyre defining the hole. In particular, the adhesive dispensing arrangement may include a control unit, adhesive storage tank, metering valve and rotary spray, and may be based on components available from: Ecolab Engineering GmbH, of Raiffeisenstraße <NUM>, <NUM> Siegsdorf, Germany. These components may include a Multiline <NUM> (trade mark) control unit (https://www. ecolab-engineering. de/en/home/).

The stud insertion arrangement may include a feed arrangement configured to feed a stud from a supply of studs into an insertion position in which the stud is radially spaced from and aligned with a radially extending stud receiving hole in a tyre of the roller into which the stud is to be inserted, and a stud displacement mechanism configured to displace the stud from the insertion position to insert at least an operatively inner end portion of the stud into the associated hole. The stud displacement mechanism may include an actuator which is displaceable between a retracted condition in which a stud is receivable in the insertion position and an extended condition, displacement of the actuator from its retracted condition to its extended condition displacing the stud from the insertion position into the hole in the tyre. The actuator may be a linear actuator and displacement of the actuator between its extended and retracted conditions may be effected by a pressurised fluid, e.g., hydraulically or pneumatically.

The machine may include an indexing arrangement configured to align the at least part of the adhesive dispensing arrangement and the at least part of the stud insertion arrangement with holes in the tyre to ensure accurate dispensing of the adhesive and placement of the studs.

The indexing arrangement may include a sensor which is configured to sense the position of a hole in the tyre and, in necessary adjust the position of the stud displacement mechanism to align it with the hole in the tyre into which a stud is to be displaced. The sensor may include a probe which has a tapered leading end which is insertable into a hole in the tyre and a detector arrangement for detecting lateral loading and/or displacement of the probe which would be indicative of a misalignment of the probe and hence the stud displacement mechanism relative to the holes in the tyre. The displacement mechanism, adhesive dispensing head and the probe may be laterally spaced, the spacing between which corresponds to the lateral spacing or pitch spacing of the holes in a row of holes in the tyre. Hence, in use, when the probe is inserted into a hole in a row of holes, if it is aligned with the hole there will be no lateral displacement of the probe and, by virtue of their lateral spacing relative to the probe, the displacement mechanism and the adhesive dispensing head will be aligned with other holes in the row of holes. If, however, the probe is not aligned with a hole, as it is inserted, by virtue of its tapered leading end, it will be deflected. The position of the displacement mechanism and the adhesive dispensing head will be adjusted in response to the direction and extent of the deflection of the probe to bring them into alignment with respective holes in the tyre.

The pitch spacing of the holes on different tyres may vary. Accordingly, the lateral spacing between the displacement mechanism, adhesive dispensing head and the probe may be adjustable to suit the particular hole spacing of a tyre, thereby enabling the machine to be used to install studs in tyres of different sizes and having differing spacing between the holes.

The machine may include a tool support module on which at least part of the stud insertion arrangement, adhesive dispensing arrangement and indexing arrangement are mounted and a gantry on which the tool support module is mounted and which is configured to permit displacement of the tool support module relative to a tyre supported on the support arrangement. More particularly, the gantry may be configured to permit displacement of the tool support module at least one of longitudinally, parallel with the axis of rotation, vertically, and transversely relative to the axis of rotation. In a preferred embodiment, the gantry may be configured to permit displacement of the tool support module along mutually perpendicular X, Y and Z axes.

The gantry may include a carriage which is displaceable along a first horizontal displacement path which is parallel with the axis of rotation. The machine may include a base track on which the carriage is displaceably mounted.

The gantry may include an intermediate support which is mounted on the carriage and is displaceable relative to the carriage in a second horizontal displacement path which is perpendicular to the first horizontal displacement path.

The gantry may include an upright support which is mounted on and extends upwardly from the intermediate support and on which the tool support module is mounted. The position of the tool support module on the upright support may be adjustable along a vertical displacement path. This arrangement permits displacement of the tool support module in three-dimensions, i.e., along X, Y and Z axes relative to a tyre mounted on the support arrangement.

The support arrangement may include a first pair of rollers and a second pair of rollers which are spaced longitudinally from the first pair of rollers, the rollers being rotatable about axes of rotation which are parallel with the longitudinal axis of rotation, and which are configured to support the shaft on which the tyre is mounted rotatably thereon for rotation about the longitudinal axis. The machine may include a drive arrangement for driving at least one of the rollers to rotate the shaft and hence the tyre supported on the rollers. In a preferred embodiment of the invention, the drive arrangement may be configured to drive both rollers in at least one of the first and second pairs of rollers. The drive arrangement may include a motor drivingly connected to the or each roller.

The position of one or more of the rollers may be adjustable to permit the shafts and tyres of the rollers of different sized HPGRs to be supported thereon and to permit adjustment of the rollers to ensure that the longitudinal axis of rotation extends horizontally.

According to a second aspect of the invention there is provided a method of installing studs on a roller of an HPGR as set forth in claim <NUM>.

The method may include the step of applying adhesive in the hole before the step of feeding the stud.

Each stud may have an operatively inner end which is inserted into the hole in the tyre and an operatively outer end which is intended to protrude from a radially outer surface of the tyre once the stud has been installed.

Optionally, the method includes, prior to inserting a stud, detecting if the stud is in the correct orientation such that when positioned in the insertion position the operatively inner end of the stud is facing the hole in the tyre into which the stud is to be inserted. If the stud is in the incorrect orientation, the method may include returning the stud to the supply of studs and feeding another stud from the supply of studs to the insertion position.

Optionally, applying adhesive to the hole includes inserting an adhesive dispensing head into the hole and discharging adhesive from the dispensing head onto the surface of the tyre defining the hole.

Optionally, after a stud has been installed, the method includes displacing the stud displacement mechanism laterally so that it is in registration with an adjacent hole in a row of holes in the tyre to permit a stud to be inserted into the adjacent hole.

Once studs have been inserted into all of the holes in a row of holes in the tyre, the method optionally includes rotating the tyre about a longitudinal axis of rotation so as to bring another row of holes into registration with the stud displacement mechanism to permit the insertion of studs into another row of holes.

Optionally, the method includes aligning the displacement mechanism with a hole into which a stud is to be inserted prior to displacing the stud into the hole.

These and other aspects of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:.

In the drawings, reference numeral <NUM> refers generally to a stud installation machine for installing studs in a tyre of an HPGR in accordance with an embodiment of the invention. As illustrated in <FIG>, the HPGR roller <NUM> with which the machine <NUM> is intended for use typically comprises an elongate shaft <NUM> and a hollow, cylindrical tyre <NUM> mounted on the shaft <NUM> as an interference fit.

The shaft <NUM> extends from a driven end 12a to a mounting end <NUM> and defines a bearing mounting portion 12c, 12d near each end 12a, 12b and a frusto-conical tyre mounting section 12e located between, and protruding radially from, the bearing mounting portions 12c, 12d of the shaft <NUM>. In other embodiments, the tyre mounting section 12e may be cylindrical (i.e. having a uniform, circular cross-section).

A plurality of spaced apart radially extending blind holes <NUM> open out of a radially outer surface of the tyre <NUM>. The holes <NUM> are typically arranged in circumferentially spaced rows with each row extending generally parallel to a longitudinal axis <NUM> of the roller <NUM>. As described below, the machine <NUM> is used to install studs <NUM> (best seen in <FIG>) in the holes <NUM>. In this embodiment, each row is aligned with its adjacent row, however, other configurations may be used. For example, adjacent rows may be offset from each other (equally or unequally) such that alternate rows are aligned but adjacent rows are offset.

The machine <NUM> includes a support arrangement, generally indicated by reference numeral <NUM> for supporting the tyre <NUM> and shaft <NUM> for angular displacement about the longitudinal axis <NUM>. The machine <NUM> further includes a stud insertion arrangement, generally indicated by reference numeral <NUM> (see <FIG>), which is configured to insert studs into the holes <NUM> in the tyre <NUM> as part of the tyre manufacturing process.

The stud installation machine <NUM> further includes an adhesive dispensing arrangement, generally indicated by reference numeral <NUM> (see <FIG> and <FIG>), and an indexing arrangement, generally indicated by reference numeral <NUM> (see <FIG>).

The machine <NUM> includes a base, generally indicated by reference numeral <NUM>. The base <NUM> includes a pair of parallel elongate longitudinally extending base members <NUM> and end members <NUM> which are connected to the ends of the base members <NUM>.

The support arrangement <NUM> includes a first pair of rollers <NUM>, <NUM> and a second pair of rollers <NUM>, <NUM>. Each pair of rollers (i.e. the first pair <NUM>, <NUM> and the second pair <NUM>, <NUM>) supports one of the bearing mounting portions 12c, 12d, thereby supporting the HPGR roller <NUM> and allowing rotational movement thereof.

A first roller support structure <NUM> supports the rollers <NUM>, <NUM> for rotation about parallel axes of rotation which are parallel with the longitudinal axis <NUM>.

A second roller support structure <NUM> supports the rollers <NUM>, <NUM> at a position which is longitudinally spaced from the first pair of rollers <NUM>, <NUM> such that the rollers <NUM>, <NUM> are rotatable about parallel axes which are parallel with the longitudinal axis <NUM>.

The support structures <NUM>, <NUM> are configured to permit the lateral spacing between the rollers <NUM>, <NUM> and <NUM>, <NUM> to be adjusted in order to support shafts <NUM> of different diameters. In addition, the second support structure <NUM> is longitudinally displaceable along the base members <NUM> in order to permit the longitudinal spacing between the first roller support structure <NUM> and second roller support structure <NUM> to be adjusted, Further, the second roller support structure <NUM> is supported on adjustable shims of jacks <NUM> to permit the level of the second pair of rollers <NUM>, <NUM> to be adjusted to ensure that, in use, the longitudinal axis <NUM> extends horizontally.

The machine <NUM> includes a drive arrangement which comprises a pair of motors <NUM>, <NUM> which are drivingly connected to the rollers <NUM>, <NUM>, respectively, to rotate the rollers <NUM>, <NUM> and the shaft <NUM>, in use, as described in more detail below.

The machine <NUM> includes a tool support module, generally indicated by reference numeral <NUM> (best seen in <FIG> and <FIG>) on which at least part of the stud insertion arrangement <NUM>, adhesive dispensing arrangement <NUM> and indexing arrangement <NUM> are mounted.

The tool support module <NUM> is mounted on a gantry <NUM>.

The gantry <NUM> includes a carriage <NUM> which is mounted for displacement in the direction of arrow <NUM> along a pair of parallel tracks <NUM> which extend horizontally and parallel with the longitudinal axis <NUM>. The gantry <NUM> further includes an intermediate support <NUM> which is mounted on the carriage <NUM> and displaceable in a horizontal plane in the direction of arrow <NUM>, i.e., perpendicular to the direction in which the carriage <NUM> is displaceable (best seen in <FIG>). The gantry <NUM> further includes an upright support <NUM> which is mounted on the intermediate support <NUM>. The tool support module <NUM> is mounted on the upright support <NUM> and is vertically displaceable thereon in the direction of arrow <NUM>. Hence, the tool support module <NUM> is effectively displaceable about mutually perpendicular X, Y and Z axes.

With particular reference to <FIG> and <FIG> of the drawings, the stud insertion arrangement <NUM> includes a stud support <NUM> which is configured to support a stud <NUM> in an insertion position in which the stud is radially spaced from and aligned with a radially extending stud receiving hole <NUM> in the tyre <NUM>.

The tool support module <NUM> includes a hollow housing <NUM> having front face <NUM>. The stud support <NUM> is mounted in the housing <NUM> in registration with a hole <NUM> in the front face <NUM>. An adjustable stud guide <NUM> is mounted on the front face <NUM> and includes a support ring <NUM>, which is in registration with the hole <NUM>, and a plurality of circumferentially spaced radially extending adjustment screws <NUM> which protrude into a central opening defined by the ring <NUM>. By adjusting the position of the adjustment screws <NUM> the effective size of the opening can be adjusted to suit the diameter of the studs <NUM> which are being installed.

The stud insertion arrangement <NUM> includes a feed arrangement, generally indicated by reference numeral <NUM>, configured to feed studs <NUM> from a storage bin <NUM> to the stud support <NUM>. As can best be seen in <FIG> of the drawings, the feed arrangement <NUM> includes a first stud lift <NUM> configured to pick up a stud <NUM> from the bin <NUM> and feed it to an intermediate platform <NUM>. Tile feed arrangement <NUM> includes a second stud lift <NUM> which is configured to displace a stud from the intermediate platform <NUM> onto an upper end of a slide <NUM> along which the stud slides downwardly, under the influence of gravity, onto the stud support <NUM> in which it is in an insertion position ready to be inserted into a hole in the tyre.

As can be seen in <FIG> of the drawings, each stud <NUM> has an operatively inner and <NUM> which is domed or semi-hemispherical in shape and an operatively outer end <NUM>.

The feed arrangement <NUM> includes a sensor <NUM>, typically an optical sensor, which is positioned to sense the orientation of a stud on the intermediate platform <NUM>. If the stud is in the correct orientation, i.e., whereby the operatively inner end <NUM> will be inserted into a hole in the tyre as described in more detail below, then the stud is displaced by means of the second lift <NUM> and discharged onto the slide <NUM>. If, however, the sensor <NUM> determines that the stud is in the incorrect orientation, then the stud is discharged from the intermediate platform <NUM> back into the bin <NUM> and a fresh stud <NUM> is displaced from the bin <NUM> by means of the lift <NUM> onto the intermediate platform <NUM>. Only when a stud <NUM> which is in the correct orientation is sensed is the stud displaced from the intermediate platform <NUM> via the second lift <NUM> and onto the slide <NUM>,.

The stud insertion arrangement <NUM> further includes a stud displacement mechanism, generally indicated by reference numeral <NUM> which comprises a pneumatically activated ram <NUM> which is displaceable between a retracted position, in which a stud is receivable on the stud support <NUM> and an insertion position or extended position in which the ram displaces the stud forwardly from the stud support through the hole <NUM> and ring <NUM> into a hole <NUM> in the tyre <NUM>.

The adhesive dispensing arrangement <NUM> includes an extendable arm <NUM> which extends through a hole <NUM> in the front face <NUM> of the housing <NUM>. A dispensing head <NUM> is mounted on a free or protruding end of the arm '<NUM>. Tile arm <NUM> is connected to a pressurised adhesive supply <NUM> and is configured to be displaced between a retracted position in which it is clear of the tyre <NUM> and an extended position in which the dispensing head <NUM> is inserted into a hole <NUM> in the tyre where adhesive can be dispensed from the dispensing head <NUM> onto the surface of the tyre defining the hole <NUM>. A collection receptacle <NUM> is provided to collect any excess adhesive which may drip from the dispensing head <NUM>.

The indexing arrangement <NUM> includes a sensor <NUM> (such as an inductive sensor) configured to sense the position of a hole <NUM> in the tyre <NUM> and a control system configured, if necessary, to adjust the position of the tool support module <NUM> (for example, in the direction of arrows <NUM> or <NUM>) to align the stud guide <NUM> and adhesive dispensing arm <NUM> with holes <NUM> in the tyre <NUM> as described in more detail below.

The sensor <NUM> is coupled to a probe <NUM> which protrudes through a hole <NUM> in the front face <NUM> of the housing <NUM> and is displaceable between a rest or retracted position and an extended position. The probe <NUM> has a tapered leading end <NUM> and the sensor <NUM> includes one or more inductive sensors (such as inductive analogue proximity sensors) for detecting transverse (such as lateral) loads on the probe <NUM>.

The machine <NUM> further includes a stud feed arrangement, generally indicated by reference numeral <NUM> configured to feed studs from a storage receptacle or hopper <NUM> into the bin <NUM>.

In various HPGR rollers, the spacing between holes in a row may be different. In order to enable the machine <NUM> to be used with different sizes of tyres <NUM>, the arm <NUM> and probe <NUM> are mounted in the housing such that they are laterally displaceable to permit the relative lateral spacing between the probe <NUM>, arm <NUM> and stud support <NUM> to be adjusted to correspond to the pitch spacing between the holes in the particular tyre <NUM> into which the studs <NUM> are being inserted.

In use, the machine <NUM>, when installed, is set up such that the rollers <NUM>, <NUM>, <NUM>, <NUM> are positioned to support the shaft <NUM> with the longitudinal axis <NUM> extending horizontally. In this regard a laser alignment device, generally indicated by reference numeral <NUM> (<FIG>), may be used.

With particular reference to <FIG> of the drawings, the position of the housing <NUM> is adjusted such that the holes in the front face <NUM> through which the stud <NUM>, arm <NUM> and probe <NUM> protrude are at the same height as the longitudinal axis <NUM> aligned with a row of holes <NUM> in the tyre <NUM>. In addition, the housing <NUM> is positioned at a desired radial spacing from the radially outer surface of the tyre <NUM>. With a stud <NUM> positioned on the stud support <NUM>, the probe <NUM> is extended (<FIG>) into a hole <NUM> in the tyre <NUM>.

If the probe <NUM> is aligned with the hole <NUM>, then it will not touch the sides of the hole <NUM> and no lateral forces will be applied to the probe <NUM> enabling it to move freely into and out of the hole <NUM>. The spacing between the probe <NUM>, arm <NUM> and stud guide <NUM> are selected to correspond to the pitch spacing between holes <NUM> in a row of holes <NUM>. Accordingly, if the probe <NUM> is aligned with a hole <NUM>, then so too will the arm <NUM> and stud guide <NUM> be aligned with other holes <NUM> in the row of holes <NUM>.

If, however, the probe <NUM> is not completely aligned with a hole <NUM>, by virtue of its tapered leading end <NUM>, as it enters a hole <NUM>, a transverse load will be applied to the probe <NUM>. The sensor <NUM> is configured to determine the direction and extent of the displacement of the housing <NUM> which is required to bring the probe <NUM> into alignment with the hole <NUM> and therefore also to bring the arm <NUM> and stud guide <NUM> into alignment with adjacent holes <NUM> in the row. The sensor <NUM> communicates this direction and distance information to a controller (not shown) that moves the tool support module <NUM> accordingly so that the probe <NUM> is brought into alignment with the respective hole <NUM>.

As illustrated in <FIG> of the drawings, once the displacement of the housing <NUM>, if required, is complete, the arm <NUM> is extended such that the dispensing head <NUM> is positioned in the hole with which it is aligned where a predetermined volume of adhesive is dispensed in the hole onto the surface of the tyre defining the sides of the hole. At the same time, the ram <NUM> is extended in order to displace the stud <NUM> into a hole in which adhesive has already been dispensed thereby inserting the stud <NUM> into the hole such that the operatively inner end of the stud abuts against the root or inner end of the associated hole.

Once the adhesive has been dispensed, the arm <NUM> is retracted. Further, once the stud has been inserted into the hole, the ram <NUM> is retracted and a fresh stud <NUM> is fed by means of the feed arrangement <NUM> onto the stud support <NUM>. As illustrated in <FIG> of the drawings, the housing <NUM> is then displaced laterally such that the probe <NUM> is aligned with an adjacent hole in the row of holes and the process described above is repeated thereby dispensing adhesive and inserting a stud into each of the holes in the row.

Once a stud has been inserted into each hole in a row, the motors <NUM>, <NUM> are activated to rotate the shaft <NUM> and tyre <NUM> by an amount sufficient to bring a subsequent (which may be an adjacent) row of holes into registration with the probe <NUM>, arm <NUM> and stud guide <NUM> and the process described above is repeated to install studs <NUM> in each of the holes <NUM>.

If desired, to inhibit unauthorised access to the stud installation machine <NUM>, it may be enclosed within a barrier element or fence <NUM> as shown in <FIG> of the drawings.

A stud installation machine <NUM> in accordance with the above embodiment should greatly increase the speed with which studs <NUM> can be installed in the holes <NUM> in a tyre <NUM>. In addition, the machine <NUM> will permit the studs <NUM> to be installed with greater consistency (due to the defined amount of force and adhesive used) thereby reducing the risk of an incorrectly installed stud <NUM>.

Various modifications may be made to the above described embodiments within the scope of the present invention defined by the appended claims.

Claim 1:
A stud installation machine (<NUM>) for installing studs (<NUM>) in a tyre (<NUM>) of an High Pressure Grinding Roller, HPGR, which machine (<NUM>) includes:
(i) a support arrangement (<NUM>) configured to support a tyre (<NUM>) and a shaft (<NUM>) on which the tyre (<NUM>) is mounted for angular displacement about a longitudinal axis (<NUM>) of rotation;
(ii) a stud insertion arrangement (<NUM>), at least part of which is displaceable relative to a tyre (<NUM>) supported on the support arrangement (<NUM>), and which is configured to insert studs (<NUM>) into holes (<NUM>) in the tyre (<NUM>); and
(iii) further comprising an adhesive dispensing arrangement (<NUM>), at least part of which is displaceable relative to a tyre (<NUM>) supported on the support arrangement (<NUM>), and which is configured to dispense adhesive into holes (<NUM>) in the tyre (<NUM>) before studs (<NUM>) are inserted into the holes (<NUM>).