FIELD OF INVENTION
This invention relates to an improved hydraulic lift cover.
BACKGROUND OF THE INVENTION
The Lift Cover is an important part of the Hydraulic Lift and required to perform the following functions:
• To carry important parts of Hydraulic Lift, namely Hydraulic Cylinder, Distributor (Control Valve), Serration Shaft (Rock Shaft) arrangement 8B supply oil drillings/ galleries.
• To serve as enclosure to the Tractor center housing with adequate sealing system having provision to avoid loss of oil through the mounting interface.
• To receive and transfer loads received from implement in use through three point linkage.
• To absorb & dissipate heat from circulation of hydraulic Oil by conduction & convection.
Strengthening ribs are provided inside the cover and hence do not help in heat dissipation through convection. Hot oil transfers the heat to cover while flowing through cover or parts mounted thereon.
Further, at critical locations lengths of the fasteners are very large resulting in inferior rigidity 8B torque retention capability.

OBJECTS OF THE INVENTION
The primary object of the present invention is to provide an improved hydraulic lift cover which overcomes disadvantages associated with the prior art.
Another object of the present invention is to provide an improved hydraulic lift cover which leads to reduced weight.
Further object of the present invention is to provide an improved hydraulic lift cover which results in improved heat dissipation capability, since some of internal ribs are brought of external side faces of the cover.
Yet another object of the present invention is to provide an improved hydraulic lift cover which results in reduced number of types of fastener.
Still another object of the present invention is to provide an improved hydraulic lift cover which results in reduced length of some of fasteners at critical locations giving advantage of better rigidity and improved grip leading to better sealing.
STATEMENT OF INVENTION
According to this invention, there is provided an improved hydraulic lift cover having reduced thickness and a plurality of strengthening ribs rearranged on external vertical surfaces of the cover.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:
Fig. 1 shows a perspective view of existing Lift Cover.
Fig. 2 shows a view of bottom side showing the stiffening ribs.
Fig. 3 shows a sectional view of the cover in a vertical plane.
Fig. 4 shows a RH perspective view of the cover of the present invention.
Fig. 5 shows a LH perspective view of the cover of the present invention.
Fig. 6 shows stress level of existing lift cover under identical boundary
conditions in respect of the assumed loading.
Fig. 7 shows stress levels of New lift cover under identical boundary
conditions in respect of the assumed loading.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:
According to this invention, there is provided an improved hydraulic lift cover having reduced thickness and a plurality of strengthening ribs rearranged on selected external vertical surfaces of the cover.
The lift cover thus obtained would provide better heat dissipation characteristics, extended duration for use and increase in oil life.
According to other aspect of the present invention, material of the cover is redistributed to have reduced grip lengths for the mounting fasteners at critical locations. This would result in reduced lengths of mounting fasteners giving advantage of better rigidity. As a combined effect , better grip & tightening torque retention would be possible.

Reference may be made to FIG 1 illustrating key areas of which get affected. Sidewall 1 carries mounting faces 4, 5 & 6 which are located at varying heights, 4 having the largest grip length. Side wall 1 also carries strengthening ribs 11(FIG 3). Top surface 2, merges with side walls 1 and carries mounting blocks 3, meant for mounting the driver seat.
FIG 2 is a plan view taken from the bottom side. It carries the strengthening ribs 7.
FIG 3 shows the inner face of the side wall 1 wherein Ribs 11 strengthen the side plate.
Reference may be made to fig. 4 wherein the present invention is provided with a plurality of ribs (12) which are brought out, mounting faces (14 8B 15) with reduced height made common with existing mounting face (5, fig. 1) and lighter mounting Block (16) by using ribbed construction.
Now, referring to fig. 5, in which ribs (17) are brought out on outer face and mounting faces (18) are made of smaller height, common with face (15).
Main thickness of the Cover at top face & sidewalls is also reduced by 15-20% in low stress zones.
Fig. 6 shows the stress levels of existing lift cover and fig. 7 shows new cover under identical conditions of presumed loading. Upon comparison with the prior art, it was found that, whereas peak stress value is comparable in both the cases , a larger area is better utilized in terms of stressing for the Lift Cover of the present invention.

FEATURES OF THE INVENTION
Redistribution of material of hydraulic lift cover to obtain desirable thickness.
Positioning of some of strengthening ribs on external surface. Reduced dimensions of some of mounting bases for cover fitment fasteners.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

WE CLAIM:
1. An improved hydraulic lift cover having reduced thickness and a plurality of strengthening ribs rearranged on external vertical surfaces of the cover.
2. An improved hydraulic lift cover as claimed in claim 1, wherein said cover's material is redistributed to have reduced grip lengths for the mounting fasteners at critical locations.
3. An improved hydraulic lift cover as claimed in claim 1 or 2, comprises of a plurality of ribs which are brought out on outer face mounting faces with reduced height made common with existing mounting face and lighter mounting Block by using ribbed construction.
4. An improved hydraulic lift cover as claimed in any of the preceding claims, wherein thickness of the cover at top face and side walls is reduced by 15-20% in low stress zones.
5. An improved hydraulic lift cover substantially as herein described with reference to the accompanying drawings.