WO2001085579A1

WO2001085579A1 - Pipe conveyor

Info

Publication number: WO2001085579A1
Application number: PCT/AU2001/000474
Authority: WO
Inventors: Robert Arthur Beatty
Original assignee: R.A. Beatty & Associates Pty Limited
Priority date: 2000-05-05
Filing date: 2001-04-27
Publication date: 2001-11-15
Also published as: AU776048B2; AU3254900A

Abstract

A pipe conveyor (10, 10A) comprises a plurality of support frames (28, 28A) which are pivotally attached to each other at connection points (29, 29B and 29C). Each of the support frames (28, 28A) carry an endless belt (16) having a forward run (15, 15A) and a return run (18). There is also provided an outer bearing member in the form of an outer spring (31) for contact with the return run (18) and an inner bearing member in the form of an inner spring (30) which is interposed between the forward run (15, 15A) and the return run (18). At least one or both of the inner spring (30) or outer spring (31) is driven by drive means (59, 63).

Description

"PIPE CONVEYOR"

This invention relates to a pipe conveyor suitable for

conveying particulate materials to a desired location.

A conventional pipe conveyor is described in AU 61 3799

having a US equivalent 551 5624. This pipe conveyor has an endless

belt having a feed end constituted by a head roller and a discharge end

constituted by a tail roller. Both the head roller and the tail roller

engage the belt to form a forward run or delivery run which may be

substantially U shaped or tubular shape, having a round cross section.

Normally the return run is U shaped and has a more shallow shape

when compared to the forward run.

The pipe conveyor of AU 61 3799 comprised a plurality of

articulated structural components of a box like shape, having opposed

side walls and a top and bottom wall, wherein adjacent articulated

structural components were separated by support frames and pivotally

attached thereto. Each support frame carried a set of peripheral rollers

or idlers^" for contacting an outer peripheral surface of the return run.

Each support frame also carried a top peripheral roller for maintaining

overlapping edges of the forward run in bearing contact. Also there

was provided spacer structure in the form of a plurality of intermediate

rollers or idlers maintained between the forward run and the return

run. Alternative spacer structure in the form of a rotatably curved axle

having a multiplicity of support discs attached thereto was also described. As a variation compressed air was also described as

suitable spacer structure.

The main purpose of the articulated structural

components was to facilitate pivotal movement of sections of the pipe

conveyor relative to each other. The pivotal attachment between each

structural component and adjacent support frames was by a universal

joint.

A particular disadvantage associated with the pipe

conveyor of AU 61 3799 was that as the length of the conveyor

increased it was difficult to apply the necessary drive power to the

endless belt. This disadvantage was reduced by applying drive power

to both the head and tail pulleys instead of just one of the. pulleys. In

other arrangements, the conveyor was divided into two or more

separate conveyors so that more power could be applied to the head

and tail pulleys at the transfer points or interconnection locations of

each conveyor. Also the tension in each of the endless belts was

reduced compared to a higher tension present when use was made of

a single endless belt. However it will be appreciated that each of

these solutions were expensive and time consuming as well as being

impractical in some cases.

Another disadvantage associated with the pipe conveyor

of AU 61 3799 was that the internal and/or external conveyor belt

support idlers required numerous rotating bearing points which were

SUBSTITUTE SHEET (RULE 26)

^■'^'viϋULt nπoαr found to be costly to buy and maintain during normal conveyor

operations.

Reference may also be made to conventional trough

conveyors which have a forward run in the shape of a shallow flat

bottomed V in cross section as hereinafter illustrated and a return run

which is in planar or flat in cross section. Such trough conveyors

were disadvantageous in that difficulty was experienced in following a

horizontal curve.

The object of the invention is to provide a pipe conveyor

which may alleviate the abovementioned disadvantages of the prior

art.

The pipe conveyor of the invention provides a plurality of

support frames which are pivotally attached to each other, wherein

each of the support frames carry an endless belt having a forward run

and a return run characterised in that each of the support frames

includes an outer bearing member for contact with the return run and

an inner bearing member interposed between the forward run and the

return run whereby at least one or both of the inner bearing member or

outer bearing member is driven by drive means.

The pipe conveyor of the invention may be installed to an

existing pipe conveyor so as to interconnect adjoining sections of the

existing pipe conveyor or alternatively may comprise a pipe conveyor

in its own right having a feed and a discharge end which may be constituted by a head roller and a tail roller, preferably as described in

AU 61 3799. Preferably each of the head roller and tail roller may be

driven by associated drive means as described hereinafter in the

preferred embodiment.

Both of the inner bearing member and the outer bearing

member may adopt a shape or orientation when attached to an

associated support frame that corresponds to the shape of the endless

belt and thus with this objective in mind both the inner bearing

member and outer bearing member may be arcuate. Preferably each

of the inner bearing member and outer bearing member are flexible or

resilient so that they may adopt an arcuate shape in practice. To this

end therefore, it is preferred that the inner and outer bearing members

are constituted by springs, although it is possible that flexible or

resilient rods formed from resilient material such as reinforced natural

or synthetic rubber or from suitable plastics materials may be used.

The inner spring is preferably wound in the opposite hand

to the outer spring. In this configuration the slight tendency for the

belt to screw, while travelling and supported by the spring bearing

members, is negated. Adjacent springs along the conveyor are also

preferably alternately configured left and right hand to further negate

any tendency for the belt to screw.

The spring bearing members used in the invention

preferably have high duty cycles in that they operate in a rotating bent configuration while imparting the necessary driving torque. Bench

testing and mathematical analysis of springs under these loading

conditions shown that acceptable spring life requires the internal

diameter of the endless belt when adopting round tubular shape to be

in the approximate range of 3-6 times the external diameter of each of

the supporting springs, and that the slower each spring rotates during

operations, the longer the service life will be. A further spring design

factor is that the wire diameter used in the spring should be in the

approximate range of 10-1 5 times less than the diameter of the

spring. Also, the steel used for the spring should be a high quality

spring steel or a "piano wire" specification steel and the pitch of each

of the springs should be such that adjacent coils just fail to touch at

the inside setting of the curved spring.

When using springs as each of the inner and outer

bearing members, each end of the springs may be connected to one or

more rigid axles or shafts mounted in bearing assemblies located in an

associated support frame and preferably in a top frame member of the

support frame.

The support frame may be of any suitable structure but

preferably includes the top frame member as described above and a

pair of side frame members. There also may be provided, if desired, a

bottom frame member, although this is by no means necessary. The

location of the bearing assemblies in the top frame member is advantageous for both maintenance and replacement purposes.

There may also be provided a plurality of articulated

structural components wherein an articulated structural component

interconnects each support frame. Preferably each structural

component is pivotally attached to each adjacent support frame and

more preferably each structural component is attached to each support

frame by a universal joint.

The provision of the articulated structural components is

useful in that they facilitate pivotal movement of sections of the pipe

conveyor relative to each other as shown in the preferred embodiment

so that the pipe conveyor may adopt a serpentine configuration or

linear configuration as may be required.

It also will be appreciated that the presence of the

articulated structural components may be dispensed with and each

support frame may be pivotally attached to each other. This may

apply for example in the case when the pipe conveyor of the invention

is installed to an existing pipe conveyor as described above.

There also may be provided one or more self-centering

spring assemblies interconnecting each support frame and adjacent

structural component or adjacent support frames as shown in the

preferred embodiment.

In another embodiment the self centering spring

assemblies and the structural components may be replaced by bar springs connecting adjacent support frames as illustrated hereinafter.

Preferably the drive means for driving the inner or outer

bearing member drives the inner bearing member. In this regard it is

preferred that the drive means comprises a drive motor connected to

an adjacent gear box, which is preferably a right angle gear box such

as a worm drive. The right angle gear box may then be connected to

a driving shaft attached to a fixed end of an associated spring.

Preferably the drive means is supported by one or more articulated

structural components.

The drive motor may be hydraulic, electrical, pneumatic

or be an internal combustion motor or any other suitable source of

power.

Thus in a preferred embodiment the driven spring is

located along the conveyor at spaced intervals and cooperate with

idler springs intermediate each driven spring. The articulation of the

driven springs may be restricted in movement relative to the idler

springs to prevent excessive drive shaft misalignment.

In another embodiment the drive motor may drive a pair

of drive shafts each associated with a particular driven spring at each

end of the structural component. This arrangement spreads the

available power over adjacent driven springs and allows the drive

motors to be spaced further apart along the conveyor when compared

to a single drive arrangement. The configuration of the forward run may comprise

substantially cylindrical form or a U shaped form as may be required.

The return run may comprise a substantially U shaped

form surrounding the forward run. This arrangement allows access to

the drive shafts of driven springs when required.

FIG. 1 is a side view of the pipe conveyor of the

invention;

FIG. 2 is a plan view of the pipe conveyor shown in FIG.

1 ; FIG. 3 is a perspective view of one form of a forward end

of the pipe conveyor shown in FIGS. 1 -2;

FIG. 4 is a perspective view of another form of forward

end of the pipe conveyor shown in FIGS. 1 -2;

FIG. 5 is a perspective view of an intermediate part of the

pipe conveyor shown in FIGS. 1 -2, showing a pair of adjacent

articulated frames thereof;

FIG. 6 is a similar view to FIG. 5, showing four

articulated frames of the pipe conveyor shown in FIGS. 1 -2, with an

associated drive means for driving the idler springs;

FIG. 7 is a plan view of a pair of articulated frames of the

pipe conveyor shown in FIGS. 1 -2, showing an alternative drive means

to that shown in FIG. 6; FIG. 7 A is a detailed view of the self centering spring

assemblies illustrated in FiG. 7;

FIG. 8 is a sectional view of the pipe conveyor of the

invention supported from an overhead track assembly or alternatively

from a lateral I-beam;

FIG. 8A is a plan view of a pipe conveyor of the invention

having a different construction to that shown in FIGS. 1 -7;

FIG. 9 is a similar view to that shown in FIG. 8 showing

the pipe conveyor of the invention fitted to an existing U shaped pipe

conveyor;

FIG. 10 is a plan view of a pipe conveyor of the invention

fitted to an existing U shaped pipe conveyor where a plurality of

adjacent articulated frames are used to re-align the existing U shaped

conveyor in another direction; and

FIGS. 1 1 -1 2 are a plan view and side view respectively of

a pipe conveyor of the invention incorporating bar springs for

interconnecting adjacent support frames instead of the self centering

spring assemblies used in FIGS. 1 -7.

The pipe conveyor 1 0, shown in FIGS. 1 -2, comprises a

feed end 1 1 and a discharge end 1 2. The feed end 1 1 comprises

loading hopper 1 3 having particulate or sized material 14 being loaded

into a forward run 1 5 of the conveyor belt assembly 1 0. The loading

hopper 1 3 is provided with a scalping plate (not shown) to prevent surge loads from the hopper 1 3 flooding forward run 1 5. The hopper

is also provided with opening 1 3A to allow material to pass through to

forward run 1 5. The particulate material or payload discharges from

the conveyor belt assembly 1 6 shown in FIG. 3 at discharge end 1 2

before the forward run belt 1 5 passes over tail pulley 1 7 before

forming a return run 1 8. The return run 1 8 then extends to head

pulley 1 9. Both the forward run 1 5 and return run 1 8 pass through

articulated structural components 20 and support frames 28.

The head pulley 1 9 is driven by drive motor 21 located

below articulated frame components 20. Drive motor 21 has drive

shaft 22 which is coupled to right angle gear box 23. Gear box 23

drives transverse shaft 24 which has pulleys or sprockets 26. Each

pulley 26 is connected to head pulley 1 9 by a belt drive 25. Tail

pulley 1 7 is driven by a similar arrangement as shown in FIGS. 1 -2.

Head pulley 1 9 is supported by support structure 27. The support

frames 28 are pivotally attached to articulated structural components

20 at a top location 29A and bottom location 29B, as shown in FIG.

3. Each support frame 28 supports a pair of counter rotating springs

30 and 31 shown in FIG. 3 which engage with forward run 1 5 and

return run 1 8. There are also provided spring assemblies 32 which

interconnect support frame 28 and structural component 20.

In FIG. 3, showing feed end 1 1 in greater detail, the

forward run 1 5 extends over head pulley 1 9, having axle 1 9A, before forming return run 18 as shown. There is also provided a scraper 33

for removing particulate material from an interior surface of return run

1 8. Also provided are a pair of oblique or angled bearing rollers or

closing idlers 35 and 35B, having axles 35A and a horizontal roller 36,

having axle 36A, which guide sides 37 and 38 of forward run 1 5 to

overlap and to form a tubular pipe 39 as shown. Each of springs 30

and 31 are attached to support frame 28 by bearing assemblies 72

shown in more detail in FIG. 8.

The pair of closing idlers 35 are provided to track the

sides of the belt so that sides 37 and 38 start forming into a pipe

configuration 39. The closing idlers 35 are spaced so that the closing

idler 35B tracking the overlapping belt is placed ahead of the closing

idler 35 tracking the underlappjng belt. Both closing idler shafts are

set at a vertical rake-angle, relative to the longitudinal axis of the pipe

conveyor 10, of between 60-80 degrees. This orientation ensures the

edges of the running conveyor belt will continue to feed into the pair

of closing idlers. The pipe configuration 39 is completed when the

forward run belt passes under the first horizontal closing roller 36.

Subsequent support frames 28 also have horizontal closing rollers 79

shown in FIG. 8, which usually continuously hold the top of the pipe in

a formed pipe arrangement. Additional pairs of closing idlers can be

placed along the coaxial pipe conveyor run, if required.

FIG. 4 shows a set of impact idlers 56 provided at the loading or feed end 1 1 of the conveyor situated between forward run

15 and return run 18. These idlers absorb the impact of material

loading onto the conveyor ahead of closing idlers 36. There is also

provided belt scraper 33A for cleaning an outer surface of return run

1 8.

FIG. 5 shows self centering spring assemblies 32 which

are supported on a top plate 41 of each frame component 20. Each

spring assembly 32 includes a spring 42, spring mount 43 and an

adjustable screw threaded rod 44, which extends through opposed

ends 45 of spring mount 43 and which is secured to support bracket

46 by nut 47. There is also provided adjustment nut 48 and fixed nut

49, attaching rod 44 through spring retaining sleeves or bushes 44A

and 44B to adjacent end 45 of spring mount 43. The spring assembly

32 operates by placing the constricted spring 42 in compression when

rod 44 and bushes 44A or 44B moves in either direction as occurs

when opposing sides of the pivotal connections 29A, 29B and 29C

move during operation. This is illustrated in more detail in FIG. 7A.

Each frame component 20 includes top plate 41 , bottom

plate 52 and a pair of side plates 53. There is also provided spring

assemblies 32 interconnecting side plates 53 of frame component 20

to an adjacent support frame 28.

FIG. 5 shows an intermediate part of pipe conveyor 10

showing particulate material 14 being transported in forward run 1 5 in the form of a tubular pipe 39 and return run 1 8 having a U shape as

shown. Both the forward run 1 5 and return run 1 8 are shown having

a gradually curving orientation at 57 and this is facilitated by pivotal

connections 29A and 29B between each support frame 28 and pivotal

connections 29C between triangular ends 58 of each side plate 52 and

an adjoining support frame 28. Each spring mount 4-3 Is bolted to top

plate 41 by bolts 43A and bracket 46 Is bolted to the top of support

frame 28 by bolt 6A.

FlQ. 6 shows a ' drive assembly 53 for each of counter

rotating springs 30 and 31 , Drive assembly 59 includes drive motor

60, as well as a right angle gear box 61 which drives a drive shaft S2

connected to spring 30 shown in more detail in FIGS . 8-9. There^' is

also provided housing 62A for coupling of shaft 62 and right angle

gear box 51 , Motor 60 is mounted to mounting plate 61 A,

FIG . 7 shows an alternative drive means for springs 30

and 31 wherein drive motor 63 associated with gear box 63A drives

pulley 63B coupled to belt 64, Belt 64 engages with idler pulley 65

fixedly attached to a top plate 4-1 by belt tensioπlng support structure 66 as well as pulleys 67 and 68 of springs 30.

in FIG. 8 the drive assembly 6S for springs 30 and 31, is

shown in more detail and includes drive shaft 62 which engeass with support shaft 70 of spring 30 at 71 . Shaft 70 extends through bearing assembly .TJ-»τ-ri.Λf>.airj*x>hΛr* -tr_'. r /tt ..÷j_rn*--r_rKri 73 _{0 S r}jng 31 _, The other end 73 of spring 31 also has support shaft 70 which

engages in bearing assembly 72. In similar manner outer spring 31

has ends 74 attached to support shafts 70 which engage in bearing

assemblies 72.

In FIG. 8 support frames 28 have now been dispensed

with and replaced by support frames 28A which support not only

bearing assemblies 72 but also bearing assembly shafts 78 in sides 77

as shown. Each bearing 81 supports a peripheral roller 79 which is

oriented transversely to the axis of the forward run 1 5 and which is

responsible for maintaining each of the overlapping edges 79A and 80

of forward run 1 5 to maintain the tubular shape 39. There are also

provided locking nuts 76.

Support frame 28A also has attached thereto a

downwardly extending frame member 82 of roller track assembly 83

which has a foot 84 attached to frame member 28A as shown.

Roller track assembly 83 includes a channel part 86

which supports wheels or rollers 87 which are each supported on

tracks 91 and 92 of track member 88. Each track member 88 also

includes a top support member 89 and a web 90. Each wheel 87 is

mounted on an axle 85.

Alternatively roller track assembly 83 may be dispensed

with and frame 28A attached to a lateral beam such as I-beam 93 as

shown in phantom, wherein vertical part 94 is attached to a fixed support 92A. I-beam 93 has foot 93A attached to side 77 of support

frame 28A. There is also provided web 93B. There is also shown

links 95 which are described in more detail in FIG 8A.

A dish-shaped washer 94A, shown in phantom, is

provided at the junction between the inner spring 30 and the drive

shaft 70. The inside edge of the dish-shaped washer 94A prevents

the edge of the forward run 1 5 from leaving the inner spring 30

enclosure, as shown in FIG. 8. The outside edge of the dish-shaped

washer prevents the return run 1 8 from tracking out of the space

between the counter rotating springs 30 and 31 . Also there may be

provided a flat washer 94B at the junction between outer spring 31

and rotatable shaft 70 which further restricts the return run 1 8, from

tracking out of the space between springs 30 and 31 .

FIG. 8A shows the longitudinal separation of support of

support frames 28A by pines 98 and links 95 which can allow

conveyor 1 0A to follow the path of track member 88 in a linear

direction as shown in full outline or an arcuate direction as shown in

phantom.

FIG. 9 shows a similar view to that shown in FIG. 8

illustrating a section 10A of the pipe conveyor of the invention being

applied to an existing trough conveyor 100. There is also shown

opposed plates 99 of support frame 28A interconnected by nut and

bolt assemblies 98. Pipe conveyor 1 0A is shown in broader detail in FIG. 10, which shows section 10A having a plurality of frame

structures 28A being attached to fixed supports 92A. This enables

two sections 96 and 97 of a conventional trough conveyor 1 00 which

are interconnected by pipe conveyor section 10A to adopt a linear

orientation as shown in full outline in FIG. 10 or a curved orientation

as shown in phantom in FIG. 10. Conventional pipe conveyor 1 00 is

also provided with conventional support structures 1 01 .

In FIG. 9 the difference between the orientation of each

of the forward and return runs of a pipe conveyor constructed in

accordance with the invention and the prior art is shown. In the pipe

conveyor section 10A there is shown forward and return runs 1 5A

and 18 in full outline compared to forward run 1 1 5A and return run

1 1 8A of conventional trough conveyor 100.

In FIGS. 1 1 -1 2 there are shown the use of bar springs

1 10 and 1 00A in interconnecting adjacent support frames 28A instead

of spring assemblies 32 previously described. Each bar spring is

attached to support frames 28A by bolts 1 1 1 . Bar springs 1 1 0 and

1 10A are alternatively placed in either side of support frames 28A as

shown. This allows flexing of forward run 1 5 as shown wherein bar

springs 1 1 0A flex as shown in FIG. 1 1 . Forward run 1 5 may adopt a

horizontal curve as shown or a vertical curve (not shown). Bar springs

10 adopt a linear configuration as shown.

In operation of the pipe conveyor of the invention, it will be appreciated that the provision of springs 30 and 31 facilitate the

application of greater power to the forward run 1 5 as well as the

return run 1 8 of pipe conveyor 10. Thus as shown in FIGS. 9-1 0 the

forward run 1 5 may be contacted by the inner surface of driven spring

30 and the return run 1 8 may be contacted by the ^"outer surface of

driven spring 30 and also the idler spring 31 . This means that greater

power or torque is applied by driven spring 30 to forward run 1 5 in

one direction and return run 1 8 in the opposite direction.

In AU 61 3799 there was provided a hydraulic cylinder for

controlling the angle of displacement at the conveyor articulated joints.

In contrast to the present invention in the preferred embodiment

provides a self centering spring, such as spring assembly 32, fitted

across the articulated joints 29A, 29B and 29C, so as to make

movement from the straight ahead position to be resisted by spring

pressure. This arrangement allows a coaxial pipe to negotiate an

imposed curve by evenly spreading the curve angle across all the

appropriate articulated joints. The self centering spring assembly

therefore prevents uneven bending of the coaxial pipe conveyor

operating around a corner at one or more articulated joints. A similar

effect is produced by operation of the bar springs shown in FIGS. 1 1 -

1 2.

In another application of this invention, the driven spring

arrangement, such as inner spring 30, may also be used to reduce the peak tensile requirements in an existing or convention troughed

conveyor. In this embodiment, the conventional troughed conveyor is

formed into a pipe conveyor of the invention by the driven spring 30

and returned to a conventional troughed conveyor, as shown in FIG.

10. There is no requirement to include an articulated joint or

articulated structural component 20 in this arrangement as the existing

troughed conveyor will be substantially fixed linear. The conveyor belt

in this application may only be wide enough to form a partially

complete internal pipe profile, but this will not affect the driven spring

capacity to add power to the overall conveyor system, and will find

useful application at some troughed conveyor installations where there

is a need to re-centre the loaded profile on the belt after having passed

through a transfer point, or similar disruption to the previously

centrally loaded profile. This intermediate driven spring arrangement

has the advantage of reducing the cost of high tensile conveyor belting

by permitting a lower tensile rated belt to be used, and/or increasing

the maximum length of a conventional troughed conveyor span.

Similarly, the driven spring arrangement may reduce the load on, or

completely replace the conventional pulley drive motor and gearbox

systems commonly used with troughed conveyors.

When using the coaxial pipe conveyor of the invention in

an underground coal mining application, it is preferred to drive the

coaxial pipe conveyor using several hydraulic motors to minimise the complexities involved in using several intrinsically safe electric motors

with their incumbent flame protected switching assemblies, operating

along the length of the conveyor.

When using the coaxial pipe conveyor in underground

mining, or tunnel applications, it is a preferred option to mount the

conveyor from an overhead track assembly affixed to the tunnel roof,

as shown in FIG. 8, which allows the coaxial pipe conveyor to easily

follow the movement behind a loading machine and to track precisely

within the confines of the tunnel. Alternatively, the pipe conveyor can

be rigidly attached to a post installation as shown by I-beam 93

attached to fixed support 92A.

In other industrial applications it is possible to mount the

conveyor on a series of wheels as shown in AU 61 3799. This allows

the conveyor to be driven or towed, in and out, at some operating

locations. At sites where high conveyor availability is required, this

feature allows for a standby coaxial pipe conveyor to be wheeled into

position while the first coaxial pipe conveyor is removed and

undergoing repairs.

When using the coaxial pipe conveyor for transporting hot

material, it is practical to use a butyl or similar belt or butyl-covered

laminate rubber belt. When using the conveyor in contact with oily

material, it is practical to use a neoprene or similar belt or neoprene-

covered laminate rubber belt. It is a feature of the belt that no

inelastic laminate layers are needed within the belt carcass.

When using the coaxial pipe conveyor to transport

reactive materials, it is possible to condition the gas above the material

loaded in .the ipe, with gas supplied from a separate conditioned gas

blower feeding in at either the delivery or feed end openings of the

coaxial pipe conveyor. This prevents chemical reaction occurring

between some conveyed materials with unconditioned air that is

problematic at some conveyor applications.

The coaxial pipe conveyor belt can be further restricted to

track straight by providing a tensile bead member 1 5B along each edge

of the belt, as shown in FIG. 8. The two belt edge bead members can

practically include a tensile core, because as the belt corners, the

change in length between the inside and outside edges of the belt

substantially cancel each other out, when folded into a pipe

configuration and allowing the internal pipe conveyor to rotate slightly

in the support idler. Any tendency for the belt to screw uncontrollably

is therefore restricted by the tension in the two beads becoming

unbalanced and seeking to realign themselves. Belt tracking is

maintained at the head and tail rollers by cutting a groove (not shown)

on both edges of the rollers to accept the tensile bead member's half-

profile.

Optionally, a positive air supply is applied to the coaxial

pipe conveyor 10 between the runs 1 5 and 1 8 at the loading point end, when transporting very dusty materials. This helps to exclude

any fine material from collecting between the two runs of the

conveyor belt. Conventional belt scrapers are provided at the delivery

end 1 2 of the outside surface of the conveyor belt to reduce the

incidence of carry back material. Preferably, the plough style belt

scraper 33 is provided at the loading end to the upper side of the

return belt (the inside belt-surface) to remove foreign particles before

they can enter between the conveyor belt and head pulley. A similar

belt scraper may optionally be placed at the tail pulley end.

In a variation of the drive assembly shown in FIG. 6,

there may be provided a double ended drive motor located at an angle

to the longitudinal axis of frame component 20 and be connected to

drive shafts 62 and 62B shown in FIG. 6 through appropriate gear

boxes or by flexible couplings. The motor in this embodiment is

aligned with respectively opposite ends of two adjacent springs 30 to

coordinate the axle directions of rotation with the motor shaft rotation.

It will also be appreciated from the foregoing that the

pipe conveyor of the invention can be towed or driven to a desired

location and then operate while following a mobile loading apparatus.

Another advantage of the pipe conveyor of the invention

is that two or more similar pipe conveyors of the invention can be

operated wherein a first pipe conveyor can be independently driven

from an installation site and be rapidly replaced by a second or subsequent standby pipe conveyor at the installation site.

An advantage of using a pipe conveyor of the invention

to interconnect adjacent conventional pipe conveyors or trough

conveyors is that a misaligned conveyor payload near one edge of a

first conventional conveyor is correctly aligned by the pipe conveyor of

the invention before moving to the centre of the second or subsequent

conventional conveyor.

It will also be appreciated from the foregoing that while it

is preferred to drive inner spring 30 it is within the scope of the

invention to also drive outer spring 31 or alternatively both of springs

30 and 31 as may be required. It will be appreciated that spring 31

also functions as a suitable spacer to space forward run 15 from

return run 1 8.

Claims

The Claims defining the invention are as follows:

1 . A pipe conveyor comprising a plurality of support

frames which are pivotally attached to each other wherein each of the

support frames carry an endless belt having a forward run and a return

run characterised in that each of the support frames include an outer

bearing member for contact with the return run and an inner bearing

member interposed between the forward run and return run whereby

at least one or both of the inner bearing member or outer bearing

member is driven by drive means.

2. A pipe conveyor as claimed in claim 1 installed to

an existing pipe conveyor so as to interconnect adjoining sections of

the existing pipe conveyor.

3. A pipe conveyor as claimed in claim 1 having a

feed end constituted by a head roller and a discharge end constituted

by a tail roller.

4. A pipe conveyor as claimed in claim 3, wherein

each of the head roller and tail roller are driven by drive means

associated therewith.

5. A pipe conveyor as claimed in any preceding claim,

wherein the inner and outer bearing members are constituted by

springs.

6. A pipe conveyor as claimed in claim 5, wherein an

inner spring constituting the inner bearing member is wound in an opposite hand to an outer spring constituting the outer bearing member.

1. ^' A pipe conveyor as claimed in claim 6, wherein

each of the inner springs and outer springs are connected to one or

more rigid axles or shafts mounted in bearing assemblies located in an

associated support frame.

8. A pipe conveyor as claimed in claim 7, wherein the

bearing assemblies are located in a top frame member of the support

frame.

9. A pipe conveyor as claimed in any preceding claim,

further including a plurality of articulated structural components,

wherein a respective articulated structural component interconnects

each support frame.

1 0. A pipe conveyor as claimed in claim 9, wherein

each structural component is attached to each support frame by one

or more universal joints.

1 1 . A pipe conveyor as claimed in claim 9 or 10,

wherein there is provided one or more self-centering spring assemblies

interconnecting each support frame and adjacent structural

component.

1 2. A pipe conveyor as claimed in claim 9 or 1 0,

wherein there is provided one or more self-centering spring assemblies

interconnecting adjacent support frames.

1 3. A pipe conveyor as claimed in claim 9 or claim 1 0,

wherein there is provided one or more bar springs interconnecting

adjacent support frames.

1 4. A pipe conveyor as claimed in any preceding claim,

wherein the drive means drives the inner bearing member.

1 5. A pipe conveyor as claimed in claim 1 4, wherein

the drive means comprises a drive motor connected to a right angle

gear box, which is connected to a driving shaft attached to a fixed end

of an associated bearing member.

1 6. A pipe conveyor as claimed in any one of claims 9-

1 5, wherein the drive means is supported by one or more of the

articulated structural components.

1 7. A pipe conveyor as claimed in any preceding claim,

wherein the driven bearing member is located along the conveyor at

spaced intervals and cooperates with idler bearing members

intermediate each driven bearing member.

1 8. A pipe conveyor as claimed in any one of claims

14-1 7, wherein the drive means drives a pair of drive shafts each

associated with a particular driven bearing member at each end of the

structural component.

1 9. A pipe conveyor as claimed in any preceding claim,

wherein the forward run has a configuration which adopts a

substantially cylindrical form.

20. A pipe conveyor as claimed in any preceding claim,

wherein the forward run has a configuration which adopts a

substantially U shaped form.

21 . A pipe conveyor as claimed in any preceding claim,

wherein the return run has a configuration which adopts a

substantially U shaped form.

22. A pipe conveyor as claimed in any preceding claim,

wherein there is provided a pair of closing idlers to close adjacent

sides of the forward run so as to form a pipe configuration.

23. A pipe conveyor as claimed in any preceding claim

wherein each of the support frames have horizontal closing idlers to

continuously hold the top of the pipe configuration in a forward pipe

arrangement.

24. A pipe conveyor as claimed in any preceding claim

supported from an overhead track assembly.

25. A pipe conveyor as claimed in any preceding claim

attached to a lateral structural beam.

26. A pipe conveyor as claimed in any one of claims 7-

25 including a disk shaped washer provided at a junction of the inner

bearing member and the support shaft.

27. A pipe conveyor as claimed in any one of the

claims 7-26 including a flat washer provided at a junction of the outer

bearing member and the support shaft.

28. A pipe conveyor as claimed in any preceding claim

wherein the endless belt has a tensile bead member along each edge

of the belt.

29. A pipe conveyor substantially as herein described

with reference to the accompanying drawings.