DESC:DESCRIPTION

FIELD OF THE INVENTION:
The present invention relates to an operator protective structure for motor grader. Particularly, the present invention relates to an operator protective structure for motor grader to withstand impact loads during rollover accidents.

BACKGROUND OF THE INVENTION:
Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

Motor grader is a self-propelled, versatile machine widely used for haul roads construction and maintenance in construction applications, mining areas and also used for clearing the snow in snow fall area. Motor grader is often required to work in rugged terrains with uneven and slippery surfaces. Probability of rollover in motor grader is more due to the high centre of gravity of the motor graders. Operator controls the vehicle operations like steering, braking and work attachment by sitting inside the cabin.

As per international standards, the operator must wear seat belt. The integrated cabin or shell cabin with independently mounted Operator safety structure is expected to safe guard the operator during rollover accidents.

The traditional roll over protective structures (ROPS) structural cross section is of higher size which leads to reduction in visibility of the operator and cabin's interior space.

In traditional roll over protective structure fabricated variable cross section (without internal strengthening) vertical members are used to withstand Roll over impact loads. Further, it is used with shell type cabins which is bulky in volume and is not user friendly.

Integrated ROPS cabins are available in many competitor model vehicles in which ROPS structure and shell cabin are merged together to achieve ROPS requirements. Some spine type ROPS structures are also available to meet ROPS standard requirements which is of single pillar.

Real time Roll angle display also has been used in some of the latest competitor models to give prior warning to the operator to prevent rollover accidents.

Existing two post roll-over protective structure consists of variable tapered fabricated structure. Study confirmed that existing ROPS is occupying more space on operator compartment, which leads to increased size of rollover protective structure.

Challenges in designing Operator safety structure is to withstand the huge impact loads and absorb the energy generated during rollover. It is expected that any structural member should not enter in to the critical zone or operator survival space called Deflection Limiting Volume (DLV) during Rollover accidents as per ISO 3164 & ISO 3471 standards.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

OBJECTS OF THE INVENTION:
An object of the present invention is to provide a compact operator safety structure for motor grader.

Another object of the present invention is to provide an operator safety structure for motor grader for better visibility of the operator.

One more object of the present invention is to provide an operator safety structure for motor grader which offers better protection to the operator during rollover accidents.

Still another object of the present invention is to provide an operator safety structure for motor grader which helps in providing more cabin interior space.

Further another object of the present invention is to provide an operator safety structure for motor grader for improving the efficiency of the operator in working environment.

Yet one more object of the present invention is to provide an operator safety structure for motor grader with better structural rigidity.

These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.

SUMMARY OF THE INVENTION:
In accordance with the present invention an operator safety structure for motor grader is provided, the operator safety structure comprises a plurality of main columns, a horizontal column, a plurality of side columns, a plurality of side column reinforcement bars, a plurality of formed plates, a plate and a plurality of mounting pads. The plurality of main columns having hollow truncated pyramid shape with a plurality of uniformly varying interweaved plates of rectangular cross-section provided inside along their height are mounted on brackets provided on either side of a main frame of the motor grader with a cabin shell provided in between therein. The horizontal column is provided in between the plurality of main columns at their top portion and welded therein to form an integrated unit. The plurality of side columns are welded at both ends of the integrated unit. The plurality of side column reinforcement bars are welded in between the plurality of side columns. The plurality of formed plates are welded along the plurality of side columns. The plate placed spreading across the top of the plurality of main columns, the horizontal column, the plurality of side columns, the plurality of side column reinforcement bars and the plurality of formed plates in integrated condition and welded in position.

In an aspect, a plurality of mounting pads inserted at the lower end of the plurality of main columns and provided with a plurality of threaded holes therein facilitates in bolting the plurality of main columns over the brackets of the main frame of the motor grader.

BRIEF DESCRIPTION OF THE DRAWINGS:
The invention will now be described with reference to the accompanying drawings in which:

Figure 1 illustrates a perspective view of a motor grader mounted with an operator safety structure in accordance with the present invention;

Figure 2(a) illustrates an isometric view of an operator safety structure of figure 1;

Figure 2(b) illustrates a front view of an operator safety structure of figure 2(a);

Figure 2(c) illustrates a cross-sectional view of a main column of figure 2(b) along the line A-A;

Figure 2(d) illustrates a top view of an operator safety structure of figure 2(a); and

Figure 2(e) illustrates a side view of an operator safety structure of figure 2(a).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
A preferred embodiment will now be described in detail with reference to accompanying drawings. The preferred embodiment does not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.

Referring to the figure 1, in accordance with the present invention, there is provided an operator safety structure 100 mounted on brackets 200 provided on either side of a main frame 300 of a motor grader 500 to extend over a cabin shell 400 of the motor grader 500.

Referring to the figures 2(a), 2(b), 2(c), 2(d) and 2(e), there is provided an operator safety structure 100 comprising a plurality of main columns 102, a horizontal column 104, a plurality of side columns 106, a plurality of side column reinforcement bars 108, a plurality of formed plates 110, a plate 112 and a plurality of mounting pads 114.

The plurality of main columns 102 are hollow truncated pyramid shaped with a plurality of uniformly varying interweaved plates 102(a) of rectangular cross-section provided inside along their height as shown in the figure 2(b) and 2(c).

The horizontal column 104 is provided in between the plurality of main columns 102 at their top portion and welded therein to form an integrated unit 150 as shown in the figure 2(b). The horizontal column has integrally formed vertical extensions 104(a) at either ends for structural rigidity purposes. The plurality of side columns 106 are welded at both ends of the integrated unit 150 as shown in the figure 2(d).

The plurality of side column reinforcement bars 108 are welded in between the plurality of side columns 106 as shown in the figure 2(d) and the plurality of formed plates 110 are welded along the plurality of side columns 106 as shown in the figure 2(d) and 2(e). The plurality of formed plates 110 are tapered at their bottom surface BS as shown in the figure 2(e).

The plate 112 is placed spreading across the top of the welded structure of the plurality of main columns 102, the horizontal column 104, the plurality of side columns 106, the plurality of side column reinforcement bars 108 and the plurality of formed plates 110 and welded in position as shown in the figures 2(d) and 2(e).

The plurality of mounting pads 114 are provided with a plurality of threaded holes 114(a) therein and inserted at the lower end of the plurality of main columns 102 as shown in the figures 2(a), 2(b) and 2(e).

The configuration and method of working of the operator safety structure 100 is as follows:
The plurality of mounting pads 114 of the plurality of main columns 102 are adapted to mount on the brackets 200 of the motor grader 500 and bolted in position as shown in the figures 1 & 2(a) in such a way that the view of the operator sitting in the cabin shell 400 is wide open without any obstruction. The plurality of uniformly varying interweaved plates 102(a) provided inside the plurality of main columns 102 as shown in the figures 2(b) and 2(c) are capable of withstanding the impact loads and act as energy absorbers during the rollover accidents. The horizontal column 104 welded to the plurality of main columns 102 as shown in the figure 2(b) is capable of withstanding longitudinal forces during the rollover and the plurality of side columns 106 welded to the integrated unit 150 as shown in the figure 2(d) are capable of withstanding lateral forces during the roll over. The plurality of side column reinforcement bars 108 welded to the plurality of side columns 106 as shown in the figure 2(d) strengthens the operator safety structure 100. The plurality of formed plates 110 tapered on their bottom surface BS and welded to the plurality of side columns 106 saves the material at low stress zone and provides the space for accommodating an air conditioning unit below therein. The plate 112 of the operator safety structure 100 provides protection to the operator sitting in the cabin shell 400 of the motor grader 500 from falling over objects as shown in the figure 1.

In an aspect, the truncated pyramid shaped plurality of main columns 102 has more load bearing capacity.

Although the invention has been described herein above with reference to the embodiments of the invention, the invention is not limited to the embodiments described herein above. It is to be understood that modifications and variations of the embodiments can be made without departing from the spirit and scope of the invention.
,CLAIMS:We claim:
1) An operator safety structure (100) for motor grader (500) comprising:
a plurality of main columns (102) having hollow truncated pyramid shape with a plurality of uniformly varying interweaved plates (102(a)) of rectangular cross-section provided inside along their height, said plurality of main columns (102) mounted on brackets (200) provided on either side of a main frame (300) of said motor grader (500) with a cabin shell (400) provided in between therein;
a horizontal column (104) provided in between said plurality of main columns (102) at their top portion and coupled therein to form an integrated unit (150);
a plurality of side columns (106) coupled at both ends of said integrated unit (150);
a plurality of side column reinforcement bars (108) coupled in between said plurality of side columns (106) and a plurality of formed plates (110) coupled along said plurality of side columns (106); and
a plate (112) placed spreading across the top of said plurality of main columns (102), said horizontal column (104), said plurality of side columns (106), said plurality of side column reinforcement bars (108) and said plurality of formed plates (110) in integrated condition and coupled in position.

2) The operator safety structure (100) as claimed in claim 1, wherein a plurality of mounting pads (114) are inserted at the lower end of said plurality of main columns (102).

3) The operator safety structure (100) as claimed in claim 2, wherein said plurality of mounting pads (114) are provided with a plurality of threaded holes (114(a)).

4) The operator safety structure (100) as claimed in claim 1, wherein said horizontal column (104) is provided with integrally formed vertical extensions (104(a)) at either ends.

5) The operator safety structure (100) as claimed in claim 1, wherein said plurality of formed plates (110) are tapered on their bottom surface (BS).