AU2021106656B4 - Dispenser for blast hole liner - Google Patents

Abstract

A dispenser for blast hole liner includes a holder (140) for a roll of blast hole liner which holds the roll of blast hole liner in a dispensing position, and which allows the roll of blast hole liner to rotate relative to a base (110) of the dispenser, to enable 5 dispensing of blast hole liner from the roll in any of a number of selectable directions. The dispenser includes a loading arrangement (118, 150, 152) which provides a mechanical advantage to facilitate elevation of the roll of blast hole liner to the dispensing position.

Description

DISPENSER FOR BLAST HOLE LINER FIELD

The present disclosure relates to a dispenser for blast hole liner and especially, but

not exclusively to a dispenser for blast hole liner for facilitating handling of a heavy

roll of blast hole liner and/or facilitating deployment of blast hole liner into a blast

hole.

BACKGROUND

The use of blast hole liners to line holes drilled for receiving explosives has been

known for many decades. A known form of blast hole liner comprises a length of

.0 flexible tube made from one or more suitable polymer materials. Prior to deployment

in a blast hole, the blast hole liner the blast hole liner may be provided in a flattened

configuration, and may be provided in the form of a roll.

In an example of use of a blast hole liner, a blast hole is drilled into rock within which

it is desired to detonate an explosive charge, for example to break up a mass of rock

.5 to assist a mineral mining process. The blast hole may be one of a plurality of blast

holes within which explosives are detonated in a sequence to break up the mass of

rock. Blast holes may be drilled about 5 to 10 metres apart. The blast hole liner is in

the form of a flattened tube of suitable material (or combination of materials)

provided in the form of a roll of blast hole liner, comprising the flattened, or'lay-flat'

blast hole liner rolled multiple times around a roll core. The roll core may be in the

form of a cylindrical shell so that a rod or spindle may be positioned therethrough,

about which the roll may be rotated, to facilitate reeling of a desired length of the

blast hole liner off the roll. Blast hole liner is reeled off the roll and fed into the blast hole. The free end of the blast hole liner is weighted to assist descent into the blast hole. When the desired length of blast hole liner has been fed into the blast hole, the reeled off part of the blast hole liner is separated from the remainder of the blast hole liner which remains part of the roll. After the blast hole liner is deployed in the blast hole, explosive, such as ANFO or heavy ANFO, is inserted into the blast hole liner causing the blast hole liner to expand from its 'lay flat' configuration, so that the exterior surface of the blast hole liner abuts the interior surface of the blast hole.

The flattened configuration of a blast hole liner may be a simple flattened tube, or

may provide side regions which are folded inwardly between front and

.0 rear walls to provide smaller lay flat width of the liner for a given expanded tube

diameter. The inwardly folded side regions are sometimes referred to as gussets.

Both of these types of lay flat configuration have been known for decades, and

examples in the published prior art include US4019438, FR2706502 and more

recently Australian Innovation Patent No. 2013101658 and Australian Innovation

.5 Patent No. 2019101379, which disclose blast hole liners with a lay flat configuration

which include side regions providing expansion gussets.

One approach to providing a dispenser for blast hole liner, is disclosed in US Patent

No. 4,019,438 which discloses a 'blast hole sleeving stand' comprising a frame with

legs, which provides a spindle for placing a roll of blast hole liner thereon and from

which the blast hole liner can be fed into a blast hole. As illustrated in US Patent No.

4,019,438, the stand is placed above the blast hole (with its legs surrounding the

blast hole), and the blast hole liner is fed into the blast hole at a steep angle.

Another approach to providing a dispenser for blast hole liner, is disclosed in PCT

Application No. PCT/AU2016/051177 (Publication No. WO 2017/197427) which

discloses an apparatus including a 'freely rotatable' dispenser for holding a roll of

blast hole liner so that the blast hole liner is dispensed when pulled. The apparatus

also includes a welder for welding closed an end of a tube of blast hole liner. The

apparatus can be mounted to a vehicle, such as on the side of a tray of a utility

vehicle, and moved from one blast hole to another.

One issue encountered in using blast hole liner dispensers is that rolls of blast hole

liner often weigh in excess of 20 kg, so that it may not be easy to load them into a

.0 blast hole liner dispenser, and incorrect lifting techniques during loading may cause

injury.

Another issue is that dispensing of blast hole liner generally involves pulling the blast

hole liner, in a direction generally perpendicular to the axis of the roll of blast hole

liner, in order to rotate the roll of blast hole liner and this requires quite specific

.5 placement of the blast hole liner dispenser during use. The need to operate on a

large number of blast holes is quite common, and this involves placement of the

dispenser close to, and correctly positioned relative to, each blast hole. If the blast

hole liner dispenser is mounted on a vehicle, the operator must move the vehicle to a

suitable position relative to each blast hole, and if a position in which the vehicle is

halted is not appropriate, the operator must move the vehicle to an appropriate

position.

It would therefore be desirable to provide a blast hole liner which, at least in

preferred embodiments avoids or mitigates one or more of these issues.

Any references to methods, apparatus or documents of the prior art or related art are

not to be taken as constituting any evidence or admission that they formed, or form,

part of the common general knowledge.

SUMMARY

According to a first aspect of the present disclosure there is provided a dispenser for

blast hole liner comprising:

a holder for a roll of blast hole liner which holds the roll of blast hole liner in a

dispensing position, and which allows the roll of blast hole liner to rotate to enable

.0 dispensing of blast hole liner from the roll; and

a loading arrangement which provides a mechanical advantage to facilitate elevation

of the roll of blast hole liner to the dispensing position.

In an embodiment the loading arrangement comprises a ramp.

In an embodiment the dispenser for blast hole liner comprises a base part, and the

.5 base part comprises a ramp.

In an embodiment the ramp is integrally formed with at least part of the base part.

In an embodiment the base part is adapted to be mounted to a vehicle.

In an embodiment the base part is adapted to be mounted to a tray of a utility

vehicle.

In an embodiment the base part comprises a frame for mounting to a vehicle.

In an embodiment the frame is configured to provide a storage area for at least one

roll of blast hole liner.

In an embodiment the ramp is configured to have, in use, a bottom end thereof

substantially contiguous with the tray of a utility vehicle.

an embodiment the holder is located above at least some of the base part when the

roll of blast hole liner is in the dispending position.

In an embodiment the ramp has, in use, an angle of elevation of less than sixty

degrees.

In an embodiment the ramp has, in use, an angle of elevation of more than twenty

five degrees.

In an embodiment the loading arrangement comprises a lever arrangement.

.0 In an embodiment the lever arrangement comprises a load region adapted to receive

a spindle upon which the roll of blast hole liner can rotate in use.

In an embodiment the lever arrangement comprises a handle region via which a user

can apply force to elevate the roll of blast hole liner.

In an embodiment the lever arrangement comprises a fulcrum region about which

.5 the lever arrangement is adapted to pivot.

In an embodiment the lever arrangement comprises first and second spaced apart

arms, and each arm comprises a load region, a handle region, and a fulcrum region.

In an embodiment the lever arrangement is adapted to retain a spindle between the

load regions of the first and second arms.

In an embodiment the lever arrangement is adapted to retain a handle between the

handle regions of the first and second arms.

In an embodiment the lever arrangement is adapted to be retained in a dispensing

position by the weight of the roll of blast hole liner and/or the weight of the lever

arrangement.

In an embodiment at least one arm provides a hook configuration for retaining a roll

of blast hole liner.

In an embodiment at least one arm provides a hook configuration at the load region

thereof.

In an embodiment the hook configuration is adapted to engage and retain a spindle.

In an embodiment the lever arrangement is adapted to receive and further elevate a

.0 roll of blast hole liner which has been elevated to some degree by use of a ramp.

In an embodiment the loading arrangement comprises both a lever arrangement and

a ramp.

In an embodiment the lever arrangement is adapted to receive and further elevate a

roll of blast hole liner which has been elevated to some degree by use of a ramp part

.5 of the dispenser.

In an embodiment the holder is adapted to receive and retain a spindle adapted to

pass through the roll of blast hole liner, and on which the roll of blast hole liner can

rotate about its axis in use.

In an embodiment the holder comprises first and second spaced part parts, wherein

the space between the first and second parts provides a receiving space for

receiving a flange of a spindle shaft therein.

In an embodiment the spindle comprises an outer part for engaging a roll of blast

hole liner, and an axle, and the outer part is rotatable relative to the axle.

According to a second aspect of the present disclosure there is provided a dispenser

for blast hole liner comprising:

a holder for a roll of blast hole liner which holds the roll of blast hole liner in a

dispensing position, and which allows the roll of blast hole liner to rotate substantially

about a main axis of the roll to enable dispensing of blast hole liner from the roll; and

a base part;

wherein the holder is adapted to rotate relative to the base part, about a substantially

vertical axis, between a first rotational dispensing position and a second rotational

dispensing position, the second rotational position being angularly spaced, about

.0 said substantially vertical axis, from said first rotational position, to thereby change

the orientation of the main axis of the roll of blast hole liner relative to the base part,

so that the direction in which the blast hole liner is dispensed, relative to the base

part, can be selectively changed; and

wherein the dispenser further provides a securing arrangement for locking the holder

.5 in either selected one of the first rotational dispensing position and the second

rotational dispensing position.

In an embodiment there is provided a bearing arrangement for facilitating movement

of the holder relative to the base part.

In an embodiment the bearing arrangement comprises an inner bearing arrangement

part and an outer bearing arrangement part.

In an embodiment the inner bearing arrangement part comprises a shaft attached to

the holder located in a bearing of the base part.

In an embodiment the outer bearing arrangement part comprises a plurality of rollers

attached to the holder engaging a roller receiving part of the base part.

In an embodiment the rollers comprise wheels.

In an embodiment the roller receiving part of the base part comprises a roller receiving track.

In an embodiment the holder comprises a handle for manual operation.

In an embodiment the securing arrangement is configured to allow locking of the

holder in either selected one of a first rotational position and a second rotational

position, wherein the first and second rotational positions are angularly spaced apart

.0 by at least approximately 90 degrees, and preferably by approximately 180 degrees.

In an embodiment the securing arrangement is configured to allow locking of the holder in at least one further rotational position.

In an embodiment the base part is adapted to be mounted to a vehicle.

In an embodiment the base part is adapted to be mounted to a tray of a utility

.5 vehicle.

In an embodiment the base part comprises a frame for mounting to a vehicle.

In an embodiment the frame is configured to provide a storage area for at least one

roll of blast hole liner.

According to a third aspect of the present disclosure there is provided a dispenser for

blast hole liner comprising:

a holder for a roll of blast hole liner which holds the roll of blast hole liner in a

dispensing position, and which allows the roll of blast hole liner to rotate to enable

dispensing of blast hole liner from the roll; and a loading arrangement which provides

a ramp to facilitate elevation of the roll of blast hole liner to the dispensing position.

According to a fourth aspect of the present disclosure there is provided a dispenser

for blast hole liner comprising:

a holder for a roll of blast hole liner which holds the roll of blast hole liner in a

dispensing position, and which allows the roll of blast hole liner to rotate substantially

about its main axis to enable dispensing of blast hole liner from the roll; and

a loading arrangement which provides a mechanical advantage to facilitate elevation

of the roll of blast hole liner to the dispensing position;

wherein the holder is adapted to rotate relative to a base part of the dispenser, about

a substantially vertical axis, to thereby change the orientation of the main axis of the

.0 roll of blast hole liner, so that the direction in which the blast hole liner is dispensed,

relative to the base part, can be changed.

It should be appreciated that a dispenser for blast hole liner in accordance with the

present invention may embody more than one of the above aspects.

Further, it should be appreciated that features set out above in relation to one aspect

.5 or one or more embodiments thereof may be incorporated into other aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments in accordance with the present disclosure will be described, by way of

example, in the following Detailed Description of Embodiments which provides

sufficient information for those skilled in the art to perform the invention. The

Detailed Description of Embodiments is not to be regarded as limiting the scope of

the preceding Summary section in any way. The Detailed Description will make

reference to the accompanying drawings, by way of example, in which:

Figure 1 is a schematic side elevation view of an embodiment of a dispenser for

blast hole liner in accordance with the present disclosure, with a roll of blast hole

liner in a dispensing position;

Figure 2 is a schematic front view of the dispenser of Figure 1;

Figure 3 is a schematic plan view of the dispenser of Figures 1 and 2, with the roll of

blast hole liner omitted;

Figure 4 is a schematic plan view of the dispenser of Figures 1 to 3, further

comprising a frame to facilitate mounting to a vehicle;

Figure 5 is a schematic plan view of the dispenser of Figure 4 with parts omitted to

.0 show some internal structure;

Figure 6 is a schematic side view corresponding to the view of Figure 5;

Figure 7 is a schematic first side-view of part of a base part of Figure 5;

Figure 8 is a schematic second-side view of the part illustrated in Figure 7;

Figure 9 is a schematic internal view illustrating a lever arrangement of the

embodiments of Figures 1 to 4, in a first position;

Figure 10 is a schematic internal view illustrating the lever arrangement of Figure 9

in a second first position;

Figure 11 is a schematic bottom view of a rotatable (carousel or turntable) part of

the embodiments of Figures 1 to 4;

Figure 12 is a schematic side view of a central bearing arrangement for allowing

rotation of the rotatable part of Figure 11;

Figure 13 is a schematic side view of a spindle of the embodiments of Figures 1 to 4;

and

Figure 14 is a schematic plan view of the embodiment of Figure 4 mounted tot the

tray of a utility vehicle.

DETAILED DESCRIPTION OF EMBODIMENTS

With reference to the accompanying drawings embodiments of a dispenser for blast

hole liner in accordance with the present disclosure will now be described.

With particular reference to Figures 1 to 3, an embodiment of a dispenser for blast

.0 hole liner, generally designated by the reference numeral 100, comprises a box-like

base unit 110 which provides at least part of a base part, and a rotatable part 140,

which is rotatable relative to the box-like base unit 110 about a substantially vertical

axis (not shown) so that the generally horizontal axis of rotation of a roll 200 of blast

hole liner can be rotated to a desired orientation, to thereby adjust the direction in

.5 which position blast hole liner can optimally be dispensed.

The box-like base unit 110 comprises a first sidewall 112, a second sidewall 114, a

rear wall 116 and a front wall 118. The first and second sidewalls 112, 114 and the

rear wall 116 are substantially vertical. The front wall 118 is inclined (as can be

clearly seen in Figure 1) to provide a ramp, facilitating manual elevation of a roll of

blast hole liner 200 during loading of the roll of blast hole liner into a dispensing

position on the dispenser 100. It will be appreciated that the ramp can be regarded

as providing a mechanical advantage which facilitates elevation of the roll of blast

hole liner to an in use, dispensing, position in which blast hole liner can be dispensed

from the roll.

The box-like base unit 110 further provides a top wall 120 (see Figure 3) which

provides a generally central circular cut-out 122 to accommodate a bottom wall of

the rotatable part 140, as will be described in due course.

The top wall 120 is provided with a number of angularly spaced apart locking

apertures 124, each adjacent to, and equidistant from, the circular cut-out 122, to

enable the rotatable part 140 to be secured in a desired one of a number of

orientations. In the illustrated embodiment the top wall 120 is provided with six

angularly spaced apart locking apertures 124A to 124F. More or fewer locking

apertures are provided, and it is considered desirable to provide at least one pair of

.0 substantially diametrically opposed locking apertures, for example locking apertures

124A and 124D, to enable the rotatable part 140 to be secured in a desired one of

two opposite orientations, for example to allow blast hole liner to be dispensed in

either of two opposite directions. For a vehicle-mounted dispenser, the two opposite

directions may correspond to the two opposites side directions of a vehicle on which

.5 it is mounted. Of course, other distributions of locking apertures may be used, for

example, an embodiment with only two locking apertures, angularly spaced by

approximately 90 degrees, may be used if it is desired to give a user only the options

of aligning the holder to dispense blast hole liner to one side or to the rear of a

vehicle.

The box-like structure of the base part includes at least one bearing arrangement,

which will be described in due course, to facilitate rotation of the rotatable part 140

relative to the base part.

The rotatable part 140 comprises a bottom wall 142, which is circular and

dimensioned to fit closely within the cut-out 122, with sufficient clearance to allow free rotation of the rotatable part 140. Upstanding from the bottom wall 142 are first and second side walls 144, 146, which are somewhat part frustoconical in shape, and which in the illustrated embodiment are each made from a number of generally planar sheet metal parts which are slightly inwardly tapered bottom to top, and welded together to provide the desired wall shape. The spacing between the side walls 144, 146 is sufficient to accommodate the width of a roll of blast hole liner 200.

A holding arrangement 148, for holding the roll of blast hole liner 200 in a dispensing

position is provided generally (although not entirely) between the side walls 144,

146. In use the holding arrangement 148, allows the roll of blast hole liner to rotate

.0 to enable dispensing of blast hole liner from the roll.

The holding arrangement 148 comprises first- and second-side lever arms 150, 152.

The lever arms 150, 152 are substantially mirror images of each other so that only

the first lever arm 150 will be described in detail, and it will be appreciated that the

other corresponds. The lever arm 150 is shown more completely in Figure 9, in a

.5 position corresponding to the roll of blast hole liner being in a dispensing position.

The lever arm 150 comprises a load region 154, a handle region 156 and a fulcrum

region 158.

The load region 154, provides a receiving space 160 between closely spaced first

and second plate parts 162, 164, for receiving a flange of a spindle arrangement

1300 (shown in isolation in Figure 13) on which the roll of blast hole liner is, in use,

rotatably retained. Thus, in use, the spindle arrangement 1300 is retained between

the load regions of the respective lever arms 150, 152.

The fulcrum region 158 is rotatably attached to the adjacent side wall 144 by a pivot

shaft 166, which may be in the form of a bolt (e.g. a 12 mm diameter bolt) welded to the side wall 144. A first lever element 168 connects the load region 154 and the fulcrum region 158.

As shown best in Figure 9, a second lever element 170 extends substantially

horizontally away from the first lever element (when the lever arm 152 is in the

position corresponding to the roll of blast hole liner being in a dispensing position)

and terminates in the handle region 156. The handle regions 156 of the two lever

arms are connected by a handle 172, which in the illustrated embodiment is in the

form of a cylindrical metal tube welded to the handle regions.

The distance between the handle region 156 and the fulcrum region 158 is greater

.0 than the distance between the load region 154 and the fulcrum region 158, so the

lever arm arrangement provides a mechanical advantage when a force is applied at

the handle region 156 to lift a load (such as a roll of blast hole liner) borne by the

load region 154, by pivoting about the fulcrum region.

The rotatable part 140 further includes a securing mechanism for locking the

.5 rotational position of the rotatable part 140 relative to the base part 110. In the

illustrated embodiment the securing mechanism comprises a spring loaded bolt

catch 174 which can be operated to engage in (or, if desired for rotation of the

rotatable part 140 relative to the base part 110, retracted from) a selected one of the

angularly spaced apart locking apertures 124. Spring loaded bolt catches are known

per se, so the spring loaded bolt catch 174 will not be described in detail, but it may

be worth noting that a common example of a spring loaded bolt comprises an axially

moveable securing bolt retained between a plate proximal the handle end and a

plate distal from the handle end, with an axially compressed coil spring retained between the plate proximal the handle end and a protrusion of the bolt, to bias the bolt into an engaged position.

Figure 4 illustrates the dispenser for blast hole liner 100 of Figures 1 to 3 further

comprising a frame 400 which facilitates attachment of the dispenser 100 to a

surface such as the tray of a utility vehicle. Figure 14 illustrates, in schematic top

plan view, the dispenser 100, including the frame 400, mounted on a utility vehicle

1400, and more specifically on the tray 1402 of the utility vehicle 1400. The utility

vehicle 1400 further comprises a cabin region 1404 and a bonnet region 1406.

Figure 5 illustrates, in schematic top plan view, the frame 400 with the box-like base

.0 unit 110 and the rotatable part 140 omitted, so that interior detail can be seen.

Figure 6 illustrates, in schematic side view, the frame of Figure 5 (again, with the

base part 110 and the rotatable part 140 omitted).

The frame 400 is generally rectangular and comprises first and second longitudinally

extending outer members 402, 404, and first and second transverse outer members

.5 406,408.

The frame 400 may be considered to comprise two sections along its length, divided

by a main interior transverse member 409. The first section 410 substantially

underlies the box-like base unit 110, and the second section 412 extends away from

the box-like base unit 110. The second section 412 provides first to third upstanding

perimeter fence parts 414, 416, 418 (which may be openwork or panelled, as

desired) to define a storage region 419, for one or more spare rolls of blast hole liner.

The second part also provides fixing brackets 420 with apertures 421 via which the

frame can be bolted to a support, such as the tray of a utility vehicle.

The first section 410 provides a bearing arrangement 422 for supporting the

rotatable part 140, and facilitating its rotation. In the illustrated embodiment the

bearing arrangement comprises an outer bearing part 424 for supporting the

rotatable part 140 below a perimeter part of the circular bottom wall 142, and an

inner bearing part 426 for supporting the rotatable part 140 below a central part of

the circular bottom wall 142.

In the illustrated embodiment the outer bearing part 424 comprises a circular track

member upon which in use, wheels attached to the underside of the circular bottom

wall 142 can run, and the inner bearing part 426 comprises a cylindrical bearing

.0 assembly for receiving a shaft which extends downwardly from the centre of the

circular bottom wall 142. The frame 400 may be regarded as part of the base part of

the dispenser 100 (with the box-like base unit 110 also forming part of the base part

of the dispenser 100). It will be appreciated that the box-like base unit 110 can be

securely mounted to the frame 400 prior to use, using any suitable fixing

.5 arrangement, such as, for example, by use of bolts or other suitable fixings. Of

course, if desired, a frame which extends beyond the walls of the box-like base unit

110 need not be provided, and in this case a bearing arrangement (for example

corresponding to bearing arrangement 422) may be provided as part of the box-like

base unit, for example as part of, or mounted on, a bottom wall or subframe of the

box-like base unit.

Figures 7 and 8 are side views of the box-like base unit 110 adapted for use with the

frame 400.

As shown in Figure 7, the second side wall is provided with cutouts 701 to

accommodate longitudinal members of the frame 400, such as the first and second longitudinally extending outer members 402, 404, and any additional, internal longitudinally extending members 403 (of which two are provided in the illustrated embodiment).

Figure 8 illustrates in broken lines, a skirt 801 which extends vertically downwardly a

short distance (for example 40 mm) from the circular edge of the top wall 120 which

defines the generally central circular cut-out 122. While not related to the provision

of the frame 400, it is considered desirable to provide the skirt 801, and a

corresponding downwardly extending skirt (not shown) which extends vertically

downwardly a short distance (for example 40 mm) from the circular edge of the

.0 bottom wall 142. This may help to reduce interference between the wall edges

and/or to maintain the desired relative positions of the bottom wall 142 and top wall

120.

Figure 9 illustrates the shape and position of the lever arm 150, as described above,

in a position corresponding to the roll of blast hole liner being in a dispensing

.5 position.

Figure 10 illustrates the position of the lever arm 150 in a position into which it may

be moved in preparation for (or during) loading of a roll of blast hole liner. The lever

arm 150 may be moved by a user by movement of the handle 172 in the left to right

direction indicated by the arrow 1000. It will be appreciated that the load region 154

of the lever arm 150 has a hook-like configuration 1002, which assists engagement

and retention of a spindle at the centre of a roll of blast hole liner, and thus assists

engagement and retention of the roll of blast hole liner itself.

In use, the roll of blast hole liner is rolled up the ramp so that the ends of the spindle

are engaged and retained by the hook-like configuration at load region 154 of each lever arm 150, 152. The roll of blast hole liner can then be moved into the dispensing position by a user by movement of the handle 172 in the right to left direction indicated by the arrow 1000. The user thus has the benefit of mechanical advantage provided by the ramp, and of mechanical advantage provided by the lever arms, in elevating the roll of blast hole liner to the dispensing position, and does not have to exert a force equivalent to the full weight of the roll of blast hole liner.

As shown in Figure 9, the dispenser provides a stop member 900 which engages

with the lever arm, for example with part of the load region 154 of the lever arm 150,

to prevent the lever arm 150 passing the dispensing position. When the load region

.0 154 of the lever arm 150 engages the stop member 900, the bottom of a retaining

recess 902, provided at the load region 154 to retain the spindle, has passed over

the pivot shafts 166 of the lever arms, so that the weight of a roll of blast hole liner

will tend to prevent the lever arms from moving towards the loading position. This

may be regarded as retention by an over-centre arrangement. It will also be

.5 appreciated that in the dispensing configuration the centre of gravity of the lever

arrangement (comprising the lever arms 150, 152 and handle 172) is substantially to

the left (as illustrated in Figure 9) of the pivot shafts 166, so the weight of the lever

arrangement itself will also tend to prevent the lever arms from moving towards the

loading position. Accordingly, no securing mechanism for locking the lever arms in

the dispensing position is included in the illustrated embodiment. However, if found

to be desired or necessary, such a securing mechanism could be provided, for

example by providing one of a spring loaded bold and a securing aperture on one of

the lever arms 150 or 152, and the other of the spring loaded bolt and the securing

aperture on (or in) a plate attached at a suitable position on the adjacent side wall

144 or 146. In the illustrated embodiment, when the lever arm 150 is in the dispensing position the stop member 900 overlies the retaining recess 902 preventing inadvertent upwards motion of the spindle and roll of blast hole liner, and thereby securing the roll of blast hole liner.

Figure 11 illustrates the underside of the rotatable part 140 and, more specifically,

the parts of the bearing arrangement which are attached to the underside of the

bottom wall 142. As illustrated, the underside of the bottom wall 142 provides outer

bearing parts in the form of first to fourth wheels 1102, which engage and run on the

circular track member of outer bearing part 424. As illustrated in the inset of Figure

11, each wheel may, for example, be mounted on a bracket comprising first and

.0 second side plates (of which a first side plate 1101 is shown) with a wheel shaft

1103, about which the wheel 1102 can rotate, mounted between the comprising first

1101 and second side plates and through the wheel 1102. In the illustrated

embodiment the underside of the bottom wall 142 provides an inner bearing part in

the form of a shaft 1104 (for example mounted on a plate 1212, which is mounted to

.5 the bottom wall 142 via reinforcing members 1216) which extends downwardly from

the centre of the circular bottom wall 142 and engages with the cylindrical bearing

assembly of the inner bearing part 426. Provision of both inner and outer bearing

parts is considered to improve performance and enhance stability and appropriate

positioning of the rotatable part 140 relative to the base part 110.

Figure 12 illustrates in schematic side view the assembled inner bearing assembly.

From bottom to top, a support member part 1202 of the frame 400, supports a metal

plate 1204 upon which a bearing housing 1206 is mounted. A shaft locking ring

1208 is provided at the top of the bearing housing 1206, and can be locked to the

shaft 1104 by use of a grub screw 1210, thus connecting the shaft 1104 and the bearing housing 1206. The shaft 1104 is attached to a metal plate 1212, by one or more welds 1214, and the plate is attached to reinforcing members 1216 which underly and support the circular bottom wall 142 of the rotatable part 140.

Figure 13 illustrates a spindle 1300 suitable for use with the dispenser 100. As

foreshadowed above, the spindle 1300 has a central shaft 1302, provided with

flanges 1304, 1306 which are adapted to be received in the respective receiving

spaces 160 provided in the load region 154 of each lever arm. The spindle further

provides a cylindrical outer part 1308 adapted to be engaged and retained in the

central cylindrical through cavity of a roll of blast hole liner. The spindle further

.0 provides a cylindrical bearing arrangement 1310, which may be of any suitable

known type, between the central shaft 1302 and the cylindrical outer part 1308 to

facilitate free rotation of the roll of blast hole liner relative to the central shaft 1302,

and thus facilitate dispensing of blast hole liner from the roll.

Embodiments in accordance with the present disclosure may be made from any

.5 suitable and suitably robust materials, such as aluminium or steel may be used. In

an embodiment the parts are primarily of steel, for example: the outer members 402,

404 of the frame 400, and the support/reinforcing members 1202, 1216 comprise 40

mm by 40 mm RHS; the internal longitudinally extending members 403 of the frame

comprise 30 mm by 30 mm RHS; and the walls 112, 114, 116, 118, 120 of the box

like base unit 110, the lever arms 150, 152, the circular track of the outer bearing

part 424, and the plates 1204, 1212 are formed from 6 mm steel plate. Suitable

dimensions for the dispenser may, of course be selected as desired and appropriate,

but by way of example, in the illustrated embodiment: the overall length of the

dispenser (including frame 400) may be approximately 1400 mm, the distance from

the base of the ramp (front wall 118) to the rear wall 116 of the box-like base unit

110 may be approximately 890 mm, the diameter of the circular bottom wall may be

approximately 550 mm, and the circular track of the outer bearing part 424 may

have an outside diameter of about 500 mm and a track width of about 50 mm.

It is to be understood that embodiments disclosed herein provide substantial

advantages over at least some previously known dispensers for blast hole liner.

The described embodiment provides a dispenser for blast hole liner which facilitates

loading of heavy rolls of blast hole liner onto the dispenser without requiring a user to

lift the roll of blast hole liner unassisted, but rather provides a ramp and a lever

mechanism, each of which provides a mechanical advantage to facilitate elevation of

.0 the roll of blast hole liner to the dispensing position. This can reduce the workload of

workers dispensing blast hole liner, and reduce the risk of lifting-related injury.

Further, the described embodiment provides a dispenser for blast hole liner which

allows blast hole liner to be dispensed in any of a number of directions without

requiring reorientation of the dispenser as a whole. For a vehicle-mounted

.5 dispenser, this can make mitigate task of correctly positioning the vehicle and can

reduce the risk of the vehicle being inappropriately positioned and having to be

moved to a more appropriate position prior to dispensing blast hole liner.

In compliance with the statute, the invention has been described in language more or

less specific to structural or methodical features. The term "comprises" and its

variations, such as "comprising" and "comprised of' is used throughout in an

inclusive sense and not to the exclusion of any additional features.

It is to be understood that the invention is not limited to specific features shown or

described since the means herein described comprises preferred forms of putting the

invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.

Claims (5)

1. A dispenser for blast hole liner comprising:

a holder for a roll of blast hole liner which holds the roll of blast hole liner in a

dispensing position, and which allows the roll of blast hole liner to rotate substantially

about a main axis of said roll of blast hole liner to enable dispensing of blast hole

liner from the roll; and

a base part;

wherein the holder is adapted to rotate relative to the base part, about a substantially

vertical axis, between a first rotational dispensing position and a second rotational

.0 dispensing position, the second rotational position being angularly spaced, about

said substantially vertical axis, from said first rotational position, to thereby change

the orientation of the main axis of the roll of blast hole liner relative to the base part,

so that the direction in which the blast hole liner is dispensed, relative to the base

part, can be selectively changed; and

.5 wherein the dispenser further provides a securing arrangement for locking the holder

in either selected one of the first rotational dispensing position and the second

rotational dispensing position.

2. A dispenser for blast hole liner according to claim 1, wherein the holder

comprises a handle for manual operation.

3. A dispenser for blast hole liner according to either preceding claim, wherein

there is provided a bearing arrangement for facilitating movement of the holder

relative to the base part, and wherein the base part is adapted to be mounted to a

tray of a utility vehicle.

4. A dispenser for blast hole liner according to any preceding claim, wherein the

base part comprises a frame for mounting to a vehicle, and the frame is configured

to provide a storage area for at least one roll of blast hole liner, the storage area

being spaced apart from the holder.

5. A dispenser for blast hole liner according to any preceding claim, further

comprising a loading arrangement which provides a mechanical advantage to

facilitate elevation of the roll of blast hole liner to the dispensing position.

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