FIELD OF INVENTION
This invention relates to hydraulic integrated direction control & shut off valve in hydraulic lift for external application.
BACKGROUND OF INVENTION
Hydraulic system of an agricultural tractor is an open center hydraulic system, which comprises of positive displacement of hydraulic pump, control valve assembly, filter assembly, cylinder, and piston, ram arm, serration shaft and control linkages. Presently agricultural tractors are equipped with feature of automatic depth and draft control system. Current applications of agricultural tractors are the field operations as well as road applications with Construction & Industrial application, tipping trolley application and many more.
During tipping trolley application (single acting cylinder) is used & Tap off is taken from Hydraulic auxiliary valve assembly (Spool valve assembly) in the most of Agricultural Tractors. It is provided in series connection with Main control valve assembly of Hydraulic lift assembly. This is associated with additional cost 85 hydraulic power consumption to the system, wherein assembly time is also increased.
Hence, the requirement of application can be met if integrated direction control valve with shut off in main control valve assembly of Hydraulic Lift is inbuilt. So that, external tap off can be controlled through main actuating draft control levers without disturbing the position of lower link/lift arm.

As current requirement for Tractor for off road application (Haulage & construction) is increasing, an optimized auxiliary control is required with main Hydraulic lift. Single acting cylinder is used in tipping trolley for unloading in trolley. Supply of Hydraulic oil is given through external tap off.
Lifting & Lowering time is evaluating parameter for the performance. As Operator is required to load /unload 5-6 times in day. Most of the Agricultural Tractor uses separate auxiliary valve (spool valve assembly) for obtaining the desired function. It consists of spool valve & connecting tubes (Pressure & Return). This system has following impact on system & customer.
1) Additional cost of control valve assembly
2) Increase in system pressure which results in additional Hydraulic power
3) Location of spool valve actuating lever away from Hydraulic control levers resulting in operator fatigue
4) Additional of Assembly time & Maintenance cost on Spool valve assembly & Tube

For optimization of above parameters, it is proposed to use main control valve assembly with modification on hydraulic lift so that main actuating control draft lever can be used for the application.
OBJECTS OF THE INVENTION
An object of the present invention is to provide hydraulic integrated direction control & shut off valve in hydraulic lift for external application, which overcomes disadvantages associated with the prior art.
Another object of the present invention is to provide hydraulic integrated direction control & shut off valve in hydraulic lift for external application, which is cost effective.
Further object of the present invention is to provide hydraulic integrated direction control 85 shut off valve in hydraulic lift for external application which is simple in construction and efficient.
STATEMENT OF INVENTION
According to this invention, there is provided Hydraulic integrated direction control & shut off valve in hydraulic lift for external application wherein the hydraulic system of tractor comprises of Hydraulic pump driven by Engine, Main control valve assembly, Cylinder and Position & Draft control levers working in a combination as shown in fig. 2.

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 : conventional system.
Fig. 2 shows: hydraulic system of the present invention.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:
The hydraulic system of tractor comprises of Hydraulic pump driven by Engine, Main control valve assembly (direction control, non return valve & bypass valve), Cylinder and Position & Draft control levers. There are three position of control spool (Neutral, Lifting & Dropping). As per actuation of lever, Oil is diverted to Cylinder through main control Valve.
In case, Oil is bypassed to external tap off before cylinder & shut off valve, it can be used for external application. During application, Knob operated shut off valve is kept in closed position to divert oil to external tap off from cylinder. Lifting and Lowering is achieved through draft control lever as shown in fig. 2.

Referring to Fig. 1 showing existing system, wherein oil from pump first reaches the spool valve assembly and depending on the position of spool valve lever; either the oil goes to external application or into the hydraulic lift.
The instant invention is directed to hydraulic integrated direction control & shut off valve in hydraulic lift for external application as shown in fig. 2. The oil directly goes into the hydraulic lift, from where if the shut off valve is closed the oil directly goes to the external tap off or, if the shut off valve is open the oil goes into the internal hydraulic cylinder. Hence, the present invention enables elimination of the spool valve assembly. Further, it stops the unnecessary circulation of pressure oil from pump to spool valve, then to external or internal system (Hydraulic lift). Oil in the present system goes directly into the internal system, thus saving power consumption.
Advantageous features of integrated direction control valve with shut off:
1) Cost saving of spool valve.
2) Reduction in the power loss.
3) Ease of operational effort & control.
4 ) Reduction in assembly Times & Maintenance cost

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. Hydraulic integrated direction control & shut off valve in hydraulic lift for external application wherein the hydraulic system of tractor comprises of Hydraulic pump driven by Engine, Main control valve assembly, Cylinder and Position & Draft control levers working in a combination as shown in fig. 2.
2. Hydraulic integrated direction control & shut off valve in hydraulic lift as claimed in claim 1, wherein the main control valve assembly comprising of direction control, non return valve and bypass valve.
3. Hydraulic integrated direction control & shut off valve in hydraulic lift as claimed in claim 1 or 2, wherein the oil directly goes into the hydraulic lift, from where if the shut off valve is closed the oil directly goes to the external tap off or, if the shut off valve is open the oil goes into the internal hydraulic cylinder.
4. Hydraulic integrated direction control & shut off valve in hydraulic lift as claimed in any of the preceding claims, is associated with the advantageous features such as herein described.
5. Hydraulic integrated direction control & shut off valve in hydraulic lift for external application substantially as herein described with reference to the accompanying drawings.