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Title:
ACCESS PLATFORM SYSTEM FOR EARTH-MOVING MACHINERY
Document Type and Number:
WIPO Patent Application WO/1997/044233
Kind Code:
A1
Abstract:
An access platform system (30) for an earth-moving machine, such as a grader (10) including a frame (11), plural ground-engaging drive members (13), a tool means (15) and an operator station (19), which access platform system includes a first deck structure including deck members (37, 38) adapted to move between an upright storage position and a flat deployed position, stairs for providing access for personnel from ground level to the first deck structure and associated safety barriers (33, 40). The first deck structure extends, in said deployed position, from the step means to the operator station (19) and the first deck structure allows, in said storage position, a substantially unobstructed view of at least a front portion of either a ground engaging drive member (13) or the tool means (15), from the operator station (19). The access platform system (30) may also include a second deck structure (32) interposed between the step means and the first deck structure and including a deck member adapted to extend along said frame (11) adjacent to an engine compartment (17) and substantially over at least one ground engaging drive member (13). The second deck structure (32) may be mounted on a suspension beam (14) of the machine (10) such that it moves in cooperation with ground engaging drive members (13). Embodiments adapted for fitment to bulldozers are also disclosed.

Inventors:
MAGNUSSEN MICHAEL WILLIAM (AU)
Application Number:
PCT/AU1997/000301
Publication Date:
November 27, 1997
Filing Date:
May 16, 1997
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ACCESS INNOVATIONS PTY LTD (AU)
MAGNUSSEN MICHAEL WILLIAM (AU)
International Classes:
B60R3/02; B62D25/22; (IPC1-7): B62D25/22; B60R3/02
Foreign References:
GB2291013A1996-01-17
US4720116A1988-01-19
US3912298A1975-10-14
US4264084A1981-04-28
US5064022A1991-11-12
US4067588A1978-01-10
GB2291381A1996-01-24
Download PDF:
Claims:
CLAIMS
1. An access platform system for mounting on a machine including a frame, plural groundengaging members, a tool means and an operator station, said access platform system comprising: a first deck structure adapted to move between a storage position and a deployed position; step means for providing access from ground level to the first deck structure; safety barrier means associated with the first deck structure; wherein the first deck structure, when in said deployed position, extends from the step means to at least adjacent the operator station; and wherein the first deck structure, when in said storage position, allows a substantially unobstructed view of an operative portion of said machine, from the operator station.
2. An access platform system as claimed in claim 1 wherein at least one member of the first deck structure is pivotally mounted with respect to said frame, whereby the deck member assumes an upright position when stored and a flat position when deployed.
3. An access platform system as claimed in claim 1 wherein at least one member of the first deck structure is slidably mounted with respect to the frame and assumes a flat position when deployed.
4. An access platform system as claimed in any one of claims 1 to 3 wherein said first deck structure comprises a plurality of deck members, each of which may be pivotally or slidably mounted as required.
5. An access platform system as claimed in any one of claims 2 to 4 wherein at least one of said deck members extends across a front side of said operator station.
6. An access platform system as claimed in any one of claims 1 to 5 wherein the safety barrier means include hand rails provided along outer edges of the first deck structure.
7. An access platform system as claimed in any one of claims 1 to 6 wherein the safety barrier means include automatically tensioned filamentary members.
8. An access platform system as claimed in any one of claims 1 to 7 further comprising actuating means which cause said first deck structure to move between the storage position and the deployed position, or vice versa, in response to manual operation of a control of the machine.
9. An access platform system as claimed in claim 8 wherein operation of the actuating means is interlocked with a brake control, such that the first deck structure may be deployed when said brake is applied and said first deck structure may be stored when said brake is released.
10. An access platform system as claimed in any one of claims 1 to 9 wherein the step means comprise a ladder or a set of stairs.
11. An access platform system as claimed in any one of claims 1 to 10 wherein the step means are adapted to be collapsible for assuming either a storage position or a deployed position.
12. An access platform system as claimed in any one of claims 1 to 11 wherein the step means is pivotally mounted on said first deck means for respective deployment or storage when said first deck structure is deployed or stored.
13. An access platform system as claimed in any one of claims 1 to 12 wherein the safety barrier means is also associated with the step means.
14. An access platform system as claimed in any one of claims 1 to 13 further comprising a second deck structure adapted to extend along said frame and substantially over at least one ground engaging member.
15. An access platform system as claimed in claim 14 wherein said step means are mounted proximate to said second deck structure and said first deck structure is adjacent to said second deck structure.
16. An access platform system as claimed in any one of claims 1 to 15 wherein the operative portion of the machine comprises at least a front portion of either a ground engaging member or the tool means.
17. A mobile machine including a frame, plural groundengaging drive members, a tool means and an operator station, wherein the mobile machine is characterised by having mounted thereon an access platform system as claimed in any one or more of the preceding claims.
18. A mobile machine as claimed in claim 17 wherein the machine is adapted for earthmoving and the tool means includes an earthworking implement.
19. A mobile machine as claimed in claim 18 wherein the machine comprises a bulldozer or a grader or a backhoe or an excavator or a front end loader or a tractor or like machine.
20. A mobile machine as claimed in any one of claims 17 to 19 and wherein the access platform system comprises a second deck structure, said structure is adapted to extend along said frame and substantially over at least one ground engaging drive member, said second deck structure being mounted such that it moves in cooperation with the ground engaging drive member(s).
21. A mobile machine as claimed in claim 20 wherein the ground engaging drive member(s) include a pair of wheels or a track mounted on a suspension beam and the second deck structure is also mounted on the suspension beam.
22. A mobile machine as claimed in claim 21 wherein the first deck structure is arranged such that, when in the storage position, clearance is provided for movement of said second deck structure during travel of the suspension beam and ground engaging drive members.
23. A mobile machine as claimed in any one of claims 17 to 22 wherein the frame of the machine further includes an articulation, whereby the control station is laterally moveable with respect to said ground engaging drive members, said first deck structure is mounted so as to move in cooperation with said control station.
24. A mobile machine as claimed in any one of claims 17 to 23 wherein the access platform system is arranged such that pivotally mounted deck members include a further pivotal mount for facilitating admittance to operative portions of the machine.
25. An access platform system as hereinbefore described with reference to the accompanying drawings.
Description:
TITLE OF THE INVENTION

"ACCESS PLATFORM SYSTEM FOR EARTH-MOVING MACHINERY"

BACKGROUND OF THE INVENTION

(a) Field of the invention

This invention relates to access platform systems for industrial

machinery, in particular a platform arrangement which provides safe and

convenient access for both machine operators and maintenance personnel

to such machines. The invention is particularly concerned with access

platform systems providing safe access to elevated positions on mobile

earth-moving machines of all types, such as graders, bull-dozers and the

like.

(b) Discussion of the Background Art

Many existing earth-moving machines merely include a step or ladder,

perhaps associated with a hand rail or grip, facilitating access for operators

to the control station of the machine, which station may be elevated some

several metres from ground level. During operation of such machines, it is

also sometimes necessary for operators to check the position or status of

certain components of their machine, such as drive wheels, earth-working

implements or other machine sub-systems, relative to geographical features,

flora, fauna or man-made obstacles. This is especially the case when the

extremities of such components are not clearly visible from the control

station. A further example which may expose operators to the risk of a fall

is when they simply wish to clean mud or grime from the external surfaces

of cabins surrounding the control station.

Accordingly, there is a risk of injury to the operator should they slip

and/or fall when climbing to an control station or standing in a precarious

position elevated on the superstructure of the machine, whether to gain a

better view of machine components or merely to clean cabin windows. This

risk is multiplied where the machine includes earth-working implements with

sharp edges or teeth, such as excavator buckets, grader blades or earth

ripping tines, in the path of a potential fall. Machine operators have

previously suffered serious injuries, including debilitating and potentially fatal

head injuries, during falls of this nature.

Maintenance personnel and operators face similar risks when access

to the engine or other operating systems, such as hydraulic lines or bearings,

is required for inspection, cleaning or lubrication purposes. This is especially

so when the machine is on-site rather than in a workshop where suitable

access frames may be available.

An example of a prior arrangement of fixed access steps and platform

with hand rails is shown in US Patent No. 4067588 in the name of Morge et

al. and assigned to Caterpillar Tractor Co. Whilst an operator may be able

to safely negotiate the rear of the cabin, this arrangement does not allow

convenient access to the front of the cabin or to the power plant for

maintenance purposes.

Several prior art arrangements merely comprise a simple retractable

step or step and hand grip for facilitating access to an operator station as set

out in the following documents. German (DD) Patent Application No.244162 in the name of VEB Baumasch Halle describes entry steps on a grader which

provide access to the driving position. The entry steps hinge at the rear end

of the vehicle and are actuated by a mechanism which is interlocked with the

vehicle hand controls for vehicle movement.

Japanese Patent Application No. 07-257281 in the name of Yutani

Heavy Industries Ltd describes a motorised step disposed in a bracket

located at the lower part of the entrance to the operator's cab on a hydraulic

excavator. An electric motor rotates the step into position at an upper side

on the entrance when the operator applies the brake.

United States Patent No. 3986724 in the name of Rivinius describes

a hydraulic power operated step which elevates the operator from a lower

position, whereby the operator may mount the step near ground level, to an

upper position adjacent the operator's cabin. This is a relatively complex and

costly device in comparison to its single purpose operation, which still

exposes an operator to the risk of a fall.

United States Patent No. 3997183 in the name of Russey and

assigned to Caterpillar Tractor Co describes an access step for a scraper.

The step and grab handle are pivoted and interconnected for simultaneous

movement, whereby movement of the grab handle extends the step to an

operable position. Although much simpler in design than the Rivinius step,

this device is relatively limited in function and would appear to require

athleticism for the operators of larger machines.

Another aspect of desirable access arrangements for earthmoving

machinery is that it should not normally obscure an operator's field of view

and/or be in such a position that it might be damaged by soil, rocks or other

debris which might be encountered during machine operations. The

importance of not obscuring the operator's view has been recognised in

United States Patent No. 3879059 also in the name of Caterpillar Tractor Co

describes a front wheel mudguard for a wheeled front-end loader which has

a reinforced lattice type box section to maintain the operator's field of vision.

The mudguard is detachably mounted on the excavator by releasable

fastening means to facilitate replacement.

United Kingdom (GB) Patent Document No. 2291013 in the name of

New Holland NV describes and access means for an agricultural vehicle

such as a harvester. The access means includes a ladder and a platform

operatively associated with one another so as to move from an operative

position to a inoperative position. Similarly, United Kingdom (GB) Patent

Document No. 2291381 in the name of Giat Industries describes a gangway

and ladder assembly mounted on a motorised breakdown vehicle. The

gangway and ladder are hinged to a platform on the chassis of the vehicle

for movement between a raised position and a lowered position, for gaining

access to the platform. The disclosed open platform arrangements pose a

finite risk of injury should an operator fall from the ladder or platform when

climbing to or from an elevated position.

BRIEF SUMMARY OF THE INVENTION

(a) Object of the Invention

It is an object of the present invention to provide an access platform

system for machines which overcomes or ameliorates at least some of the

problems of the prior art.

It is a preferred object of the invention to provide an access platform

system which provides convenient access to, and improves the safety of,

earth-moving machinery for personnel operating or maintaining said

machinery.

It is another preferred object of the invention to provide an access

platform system which provides a substantially unobstructed view of an

operative portion of earth-moving machinery from an operator station during

normal operation of said machinery.

Further objects will be evident from the following description.

(b) Disclosure of the Invention

In one form, although it need not be the only or indeed the broadest

form, the invention resides in an access platform system for mounting on a

machine including a frame, plural ground-engaging members, a tool means

and an operator station, said access platform system comprising:

a first deck structure adapted to move between a storage position and a deployed position;

step means for providing access from ground level to the first

deck structure;

safety barrier means associated with the first deck structure;

wherein the first deck structure, when in said deployed position,

extends from the step means to at least adjacent the operator station; and

wherein the first deck structure, when in said storage position,

allows a substantially unobstructed view of an operative portion of the

machine, from the operator station.

Preferably the first deck structure is pivotally mounted with respect to

said frame, such that at least one member of the first deck structure

assumes an upright position when stored and a flat position when deployed.

The first deck structure may alternatively include at least one deck

member which is slidably mounted with respect to the frame and assumes

a flat position when deployed.

Preferably said first deck structure comprises a plurality of deck

members, each of which may be pivotally or slidably mounted as required.

Optionally one of said deck members extends across a front side of

said operator station.

Preferably the safety barrier means include hand rails along outer

edges of the first deck structure.

If required, the safety barrier means include automatically tensioned

filamentary members.

Preferably, the access platform system comprises actuating means

which cause said first deck structure to move between the deployed position

and the storage position in response to the manual operation of a control of

the machine.

Most preferably said actuating means is interlocked with a brake

control, such that the first deck structure may be deployed when said brake

is applied and said first deck structure may be stored when said brake is

released.

The step means may comprise a ladder or a set of stairs, as required.

Optionally the step means are adapted to be collapsible for assuming

either a storage position or a deployed position.

Suitably the step means is pivotally mounted on said first deck means

for respective deployment or storage when said first deck structure is

deployed or stored.

If required the safety barrier means is also associated with the step

means.

In preference, the access platform system comprises a second deck

structure adapted to extend along said frame and substantially over at least

one ground engaging member.

Suitably, said step means are mounted proximate to said second deck

structure and said first deck structure is adjacent to said second deck

structure.

Preferably the operative portion of the machine visible when the first

deck structure is in the stored position includes at least a front portion of

either the ground engaging member or the tool means.

In a further form, the invention resides in a mobile machine including

a frame, plural ground-engaging drive members, a tool means, an operator

station, wherein said mobile machine is characterised by an access platform

system comprising:

a first deck structure adapted to move between a storage

position and a deployed position;

step means for providing access from ground level to the first

deck structure; safety barrier means associated with the first deck structure;

wherein the first deck structure, when in said deployed position,

extends from the step means to at least the operator station; and

wherein the first deck structure, when in said storage position,

allows a substantially unobstructed view of at least a front portion of either

a ground engaging drive member or the tool means from the operator

station.

In preference the machine is adapted for earth-moving, wherein the

tool means includes an earth-working implement.

The earth-moving machine may comprise a bull-dozer or grader or

back-hoe or excavator or front-end loader or tractor or like machine.

Preferably the earth moving machine may include a second deck

structure adapted to extend along said frame and substantially over at least

one ground engaging drive member and mounted such that the second deck

structure moves in cooperation with the ground engaging drive members.

Suitably, where the ground engaging drive members include a pair of

wheels or tracks mounted on a suspension beam, said second deck

structure is mounted on the suspension beam.

Most preferably, the first deck structure is arranged such that, when

in the storage position, clearance is provided for movement of said second

deck structure during travel of the suspension beam and ground engaging

drive members.

Preferably, where the frame includes an articulation whereby the

control station may move with respect to said suspension beam and ground

engaging drive members, said first deck structure is mounted so as to move

in cooperation with said control station.

If required the access platform system may be arranged such that

pivotally mounted deck members include a further pivotal mount for

facilitating admittance to operative portions of the machine.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

To assist in understanding the invention preferred embodiments will

now be described with reference to the following drawing figures in which:

FIG. 1 is a perspective view of a first embodiment of the invention

adapted for use with a grader;

FIG. 2 is a side elevational view of the first embodiment;

FIG. 3 is a top plan view of the first embodiment;

FIG. 4 is a top plan view of the first embodiment with the grader in an

articulated position;

FIG. 5 is a front elevational view of the first embodiment;

FIG. 6 is a side elevational view of the first embodiment with the

grader suspension in an inclined position;

FIG. 7 is a further side elevational view of the first embodiment with

the grader suspension in a declined position.

FIG. 8 is a rear elevational view of the first embodiment;

FIG. 9 is a perspective view of a second embodiment of the invention

adapted for use with a bull-dozer;

FIG. 10 is a perspective view of the second embodiment shown in a

deployed position on the bull-dozer;

FIG. 11 is a front elevational view of the second embodiment, shown

in a deployed position;

FIG. 12 is a front elevational view of the second embodiment, shown

in a stored position;

FIG. 13 is a front elevational view of a third embodiment of the

invention also adapted to use on a bull-dozer, shown in a

deployed position;

FIG. 14 is a front elevational view of the third embodiment, shown in a

stored position; and

FIG. 15 is a top plan view of the third embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring generally to FIGS 1 , 2 and 3, an access platform system 20

of a first embodiment of the invention is mounted on either side of an earth-

moving machine, here a grader 10. It will be appreciated, as shown in the

second embodiment, that some machines may only require an access

platform system mounted on one side. The grader is drawn in full in FIG. 1 ,

but only in phantom in the remaining drawing figures for clarity purposes.

The grader 10 includes a frame 11 , steer wheels 12, two pairs of drive

wheels 13 mounted on respective suspended beams 14, an earth-working

implement in the form of a blade 15 actuated by hydraulic rams 16, an

engine compartment 17 and a cabin 18 enclosing an operator's control

station 19. It will be appreciated that other tools, such as ground ripping

tines (see FIG. 8), may also be fitted to such a grader. These and other

components of a conventional grader are only described as necessary in

relation to the discussion of the embodiment of the access platform system.

The access platform system 30 includes step means in the form of a

set of stairs 31 , providing access from ground level to a fixed deck structure

32. The fixed deck structure 32 extends along one side of the grader 10 and

is located above the drive wheels 13 and adjacent to the engine

compartment 17. The steps 31 are disposed behind the rearmost of the

drive wheels in the embodiment. A safety barrier 33 incorporating a hand rail

34 is located along an outer edge of the stairs 31 and the fixed deck

structure 32. The fixed deck structure 32 is mounted on the suspension

beam 14 such that the steps 31 , fixed deck structure 32 and the safety

barrier 33 move in concert with the drive wheels 13. This mounting

arrangement for the fixed deck structure 32 provides sufficient clearance for

the drive wheels 13 during suspension travel, as illustrated by the possible

positions of the drive wheels 13 as shown in FIGS 6 and 7 of the drawings.

The fixed deck structure 32 includes a deck member which is typically

constructed of a suitable gauge metallic plate material, such that it may also

function as a mudguard for the drive wheels 13. The plate material is

preferably provided with a textured surface to reduce slippage in wet and/or

muddy conditions. Similar considerations apply to the choice of material for

the stairs 31. Other suitable materials may also be specified, for example

some plastics materials have a superior strength-to-weight ratio when

compared to metal, and may be ideal for such an application.

The access platform system 30 also includes a moveable deck

structure 35 comprising a plurality of deck members (described below)

which, when deployed as shown in FIG. 2, extend from over a forward end

of fixed deck structure 32 to a position adjacent the operator's control station

19, which position is conveniently adjacent a door 20 to the control cabin 18

of the machine. It would be preferable in the embodiment, if the door 20 to

the control cabin 18 was hinged at a front side of the opening, rather than at

the front side of the opening as typical of existing doors for grader cabins.

The movable deck structure 35 is comprised of a number of leaves or

deck members 36, 37, 38 pivotally mounted with respect to the control cabin

18, see FIGS 1 and 3. A floating deck member 36 is mounted in overlapping

relation with a forward end of the fixed deck structure 32, as shown in FIG.

2. A longitudinally extending deck member 37 is pivotally mounted on the

frame 11 adjacent a rearward edge of the deck member, for assuming either

a storage position, wherein it is upright (as shown in FIGS 1 and 5) or a

deployed position, wherein it lies flat (as shown in FIGS 2 and 3).

The movable deck structure 35 further includes a laterally extending

deck member 38, which extends across a front side of the operator station

19. The lateral deck member 38 is pivotally mounted on the frame 11 at an

inner edge of the deck member for similarly assuming either an upright

storage position or a flat deployed position, as depicted in FIG. 5.

Each of the deck members 36, 37, 38 of the structure 35 are moved

with the assistance of respective actuating means, here in the form of

hydraulic cylinders 39. Suitably the actuating means are interlocked with a

manual park brake control, such that the moveable deck members are

deployed when said park brake is applied by the operator and the members

are stored when said park brake is released. The deck members are

typically constructed of perforated or mesh sheets of metallic material, such

as expanded steel mesh, which material is used for the longitudinal deck

member 35 and lateral deck member 38 of the embodiment.

A further safety barrier 40, including hand-rails 41 , is also provided

adjacent the outer edges of the members of the movable deck structure 35.

In an optional arrangement (not shown), the further safety barrier 40 and

hand rails 41 may also fold or telescope into a storage position when the

deck members of the movable deck structure 35 are moved into the storage

position by the actuating means 39, thereby further improving the machine

operator's view from the control station.

In an alternative arrangement, a moveable deck structure could

include deck members slidably mounted in a flat position under the control

cabin 18 for deployment as desired.

FIG. 2 shows the movable deck structure 35 mounted slightly above

the level of the fixed deck structure 32, specifically to allow the floating deck

member 36 to partially overlap the fixed deck structure 32 when the floating

deck member is deployed. This mounting arrangement is particularly

suitable for use in relation to articulated earth-moving machines, as

illustrated in FIG. 4. Also shown in FIG. 2 is a transitional safety barrier

arrangement which includes, in the embodiment, a pair of filamentary

members in the form of multi-strand steel cables 42 which each extend from

the safety barrier 33 mounted on the fixed deck structure 32, to the further

safety barrier 40 mounted on the movable deck structure 35. The

filamentary members are automatically placed under a pre-determined

tension by tensioning means (not shown) so as to maintain an effective

barrier irrespective of any articulation setting of the machine (see FIG. 4) or

position of the machine on any incline or decline (see FIGS. 6 and 7).

FIG. 3 is a top plan view of the access platform system 20, when in

the deployed position. It will be appreciated that, when an access platform

system is mounted on both sides of the grader 10, a walk-way bordered by

a safety barrier means extends from the rear of the grader past the engine

compartment 17 on one side around the control cabin, past the opposite side

of the engine compartment and back to the rear of the grader. Accordingly,

personnel have convenient access to either side of the engine compartment

17 and to the control cabin 18. FIG. 3 also shows an optional central deck

structure 43 which extends forward of the control cabin 18 over the machine

frame 11. The central deck structure includes its own safety barrier 44 with

hand rails 45 and a manually deployable ladder 46. The ladder 46 provides

a secondary point of egress for a machine operator, should it be required in

an emergency situation such as a fire in the machines engine compartment.

FIG. 4 shows the grader 10 configured in a fully articulated position,

facilitated by a lockable pivot (not shown) in the frame 11 disposed in the

vicinity of the control station 19. A front portion of the grader, including the

control station 19, surrounding cabin 18 and associated movable deck

structure 35 of the access platform system 20, pivot with respect to an

assembly including the engine compartment 17, suspension beams 14 and

drive wheels 13 of the grader 10, along with the associated fixed deck

structure 32. The drawing illustrates how the partial overlap of the floating

deck member 36 and the fixed deck structure 22 is capable of maintaining

a continuous walk-way from the steps 31 to the control cabin 18, even when

the grader is locked in an articulated position.

FIG. 5 is a view looking towards the front of the grader 10 showing the

longitudinal deck member 37, the lateral deck member 38, the further safety

barrier 40 and hand rail 41 of the movable deck structure 35, on each side

of the grader. The deck members 37, 38 are shown in the upright storage

position, typically employed whilst the grader is in motion during operations.

FIG. 6 shows an extreme position of the suspension beam 14 and

drive wheels 13 which may be experienced when the grader 10 is

negotiating an incline. As discussed above, the fixed deck structure 32 is

mounted on the suspension beam 14. The arrangement of the safety barrier

33 and the stored floating deck member 36 of the movable deck structure 35

provide clearance for the fixed deck structure 32 and the frontmost of the

drive wheels 13. Similarly, FIG. 7 shows another extreme position of the

suspension beam 14 and drive wheels 13 which may be experienced when

the grader is negotiating a decline. The operation of the tensioned multi-

stand steel cables 42 comprising the transitional safety barrier is also clearly

apparent from these drawings.

FIG. 8 is a rear elevational view of the access platform system 30

mounted on a grader 10. The stairs 31 providing access from ground level

to the deck member of the fixed deck structure 32 include a pivot 47 (see

also FIG. 2) such that a lower portion 31a of the stairs is collapsible or

foldable. Further actuating means 48 are provided to pivot the lower stair

portion 31a upward in concert with the storage of the moving deck members

37, 38. A stored position of the stairs is illustrated in FIG. 6, wherein the

additional ground clearance is apparent. A roller 36a, provided on the

underside of the floating deck member 36, for engaging the deck member of

the fixed deck structure 32 is illustrated in the drawing. A cowl 49 provided

for covering the actuating means 39 for the longitudinal deck member 37 and

the lateral deck member 38 is also shown.

The access platform system of the first embodiment provides a stable

non-slip walk-way for operators and maintenance personnel alike, extending

from the rear of the grader adjacent to the engine compartment, past the

operator station and around to the front side of the control cabin. The

access platform system also includes, on its outer edges, a series of safety

barriers with hand rails providing support for personnel in the event of loss

of footing.

A second embodiment of the invention, adapted for use on a bullĀ¬

dozer will now be described with reference to FIGS 9 to 12 of the drawings.

Turning to FIG. 9, the access platform system 70 of the second embodiment

is shown mounted on a bull-dozer 50. The bull-dozer includes a frame 51

(concealed by body panels in the drawing), a ground engaging drive member

in the form of an endless track 52, which is driven by a drive sprocket 53 and

carried on a suspension beam 54.

The bull-dozer further includes an earth-working implement, in the

form of a shallow bucket-type blade 55 actuated by hydraulic rams 56, 62

and supported by a push arm. An operator's cabin 58 surrounding a control

station 59 is disposed behind the engine compartment 57 of the bull-dozer

50. The superstructure of the bull-dozer includes a shelf 61 extending from

under the door 60 to the cabin 58. As indicated above in relation to the first

embodiment, the features of a conventional bull-dozer are only described for

the purposes of providing a context for illustrating the present invention.

With reference to FIG. 10, the access platform system 70 of the

embodiment includes step means in the form of a set of stairs 71 and a

moveable deck structure 72. The moveable deck structure includes a deck

member 73, arranged for pivotal mounting 74 on the bull-dozer frame 51

adjacent one side of the engine compartment 57. Safety barrier means 75,

76 are located on outer edges of the deck member 73, and include

respective hand rails 77, 78 . The stairs 71 , which also incorporate a safety

barrier with hand rails 79, are in turn pivotally mounted 85 on the deck

member 73. Furthermore the stairs are collapsible, having a folding lower

portion 80 with an associated crank mechanism 81.

Movement of the deck structure 72 is facilitated by an actuating

means, here in the form of a hydraulic cylinder 82, although other actuators

such as rotary motors may be employed. The laterally extending rails 76, 78

of the safety barrier associated with the forward edge of the deck member

73 are pivotally mounted at each end. The inner ends of the rails are

journalled in a bracket 83 mounted on the frame of the bull-dozer adjacent

the engine compartment 57. Whilst the outer end of the rails 76, 78 are

journalled in apertures provided in a support post 84 fixed to an upper end

of the stairs 71.

It will be appreciated that, as the deck member 73 turns on the pivotal

mounts 74 under the influence of the hydraulic cylinder 82, the pivotally

mounted rails 76, 78 effectively form a quasi-parallel linkage. Furthermore

the crank mechanism 81 attached to the lower portion 80 of the stairs 71 ,

urges the lower portion to fold with respect to the upper portion thereof. The

linkage arrangement of the embodiment thus allows the access platform

system of the embodiment to be stored in a compact fashion, as illustrated

in FIG. 12. Preferably the access storage system may only be deployed

when the bull-dozer's park brake has been applied, as a further safety

measure.

The movable deck structure 72 is thus moveable between a flat

deployed position, facilitating convenient access to the operator's cabin as

shown in FIGS. 9 and 12, and an upright stored position, wherein the

operator has a substantially unobstructed view of the front portion of the

track 52 and/or the blade 55 (depending on the position of the blade at the

time) as shown in FIGS. 10 and 11.

It should be noted that, the stairs 71 are preferably fully supported by

the moveable deck structure 72 and need not rely upon the ground for

support, which ground may be uneven or broken. Furthermore when in the

deployed position, the deck member 73 is disposed adjacent to the shelf 61

and thus also the operator's control station 59. In other embodiments, for

example adapted to a bull-dozer which does not include a shelf 61 or like

structure, the movable platform 72 may include additional deck members and

safety barriers whereby an operator climbing to the elevated control station

59 may do so safely and conveniently.

It will be appreciated that, in bull-dozers without an access system 70

in accordance with the invention, operators must climb over the push arm 62

for the blade 55 and onto the track 52, both of which may be covered in

slippery mud or loose gravel. From the track 52, operators must then hoist

themselves onto the shelf 61 in order to enter the cabin 58 via door 60. The

access platform system 70 of the embodiment ameliorates the risks

associated with climbing over such machinery, by providing stairs 71 and a

deck structure 72 with associated safety barriers facilitating convenient

access to an elevated control station 59 when deployed. When the structure

is stored, the operator is afforded a substantially unobstructed view of

operative portions of the machine from the control station. Storage of the

system also reduces the possibility of collision with obstacles during machine

operations.

A third embodiment of the invention, also adapted for use on a bullĀ¬

dozer, will now be described with reference to FIGS 13 to 15 of the drawings.

The access platform system of the third embodiment comprises a deck

structure 90 including a movable deck member 91 , a safety barrier with a

support post 92 and a hand rail 93, and a set of stairs 94 pivotally attached

to an outer edge of the deck member 91. The stairs 94 include a collapsible

lower portion 96 and a hand rail 97. A further safety barrier 98 is mounted

on a pre-existing platform 99 on the bull-dozer 100.

The deck structure 90 is movable between a deployed position as

illustrated in FIG. 13 and a stored position as illustrated in FIG. 14, whereby

the deck member 91 pivots about a substantially horizontal pivot axis 101 (as

shown in FIG. 15) between a flat position and a upright position, respectively.

An actuator 102 which drives a gear set 102a coupled to the deck structure

assists with pivoting the deck member 91 and stairs 94 to and from the

storage position. The deck structure 90 is further characterised by the

manner of pivotal mounting to the chassis 103 of the bull-dozer, which

employs an upright pivot post 104. The pivot post arrangement facilitates

admittance to operative portions of the machine, here the engine

compartment 106, when the deck structure 90 is in a stored position. In the

embodiment, the stored deck structure may be pivoted, about a substantially

vertical axis 105, away from a position where the upright deck member 91

is adjacent to and otherwise covers a portion of the engine compartment

106. This arrangement facilitates admittance to the engine for the purposes

of periodic maintenance and the like.

In the deployed position the stairs 94 of the deck structure 90 are

supported over the push arm 107 of the dozer, allowing safe and convenient

access to the operator station.

In another embodiment, the access platform system of the invention

may also be conveniently demountable from the earth-moving machine, in

order to facilitate access for deep maintenance procedures and/or repairs to

said machine. The access platform system may also be adapted to

cooperate with or supersede existing access steps or ladders, such that

when the access platform system is demounted the existing steps or ladders

provide minimum access to the operator station.

Throughout the specification the aim has been to describe the

preferred embodiments of the invention without limiting the invention to any

one embodiment or specific collection of features. In particular the

embodiments described herein are adapted for fitment to a grader and a bull

dozer, however the invention made by adapted for fitment to earth-moving

and other large machinery of all types including fixed, articulated or rotating

frame machines.