CLIAMS:We Claim:

1. An e-lift system for an agricultural vehicle (100), which does not entail the presence of continuous pressure and does not require a dedicated oil source, comprising an actuator (108), a pressure maintenance valve (109), a directional control valve (110), a bypass valve (111), an oil return line (112) and a switch (not shown) for toggling the directional control valve (110); said system (100) being adjunct to an existing power steering, wherein an oil return port (106) of the power steering system acts as an oil input port for the e-lift systems (100) and the bypass valve (111), the actuator (108), the directional control valve (110) and the pressure maintenance valve (109) are being connected between oil return port (106) and the oil return line (112) one after the other and in parallel to each other.

2. The e-lift system for an agricultural vehicle (100) as claimed in claim 1, wherein the directional control valve (110) is a solenoid valve.

3. The e-lift system for an agricultural vehicle (100) as claimed in claim 2, wherein the solenoid valve is a three port two position directional control valve.

4. The e-lift system for an agricultural vehicle (100) as claimed in claim 2, wherein the solenoid valve is a two port two position directional control valve.
,TagSPECI:TITLE OF THE INVENTION: E-LIFT SYSTEM FOR AN AGRICULTURAL VEHICLE

FIELD OF THE INVENTION

The present invention relates to a system for lifting and lowering of the implements/accessories attached to an agricultural vehicle.

BACKGROUND OF THE INVENTION

In an agricultural vehicle different types of implements/accessories such as tiller, ploughs etc. are used for different kinds of operations. Generally, the lifting and lowering operations of such accessories are controlled by a hydraulic system. Conventionally, the hydraulic system used for such operations entails availability of continuous pressure and also work well with the presence of high volume of hydraulic oil within the system. To maintain continuous pressure and high availability of hydraulic oil, it is necessary to keep a dedicated bigger oil source for the system or use of transmission oil that is available in bulk. Further, the high pressure causes the system to gets heated quickly and thus affects the system performance and life.

There is therefore a need in the art for a system that does not require the presence of continuous pressure and without having a dedicated oil source.

OBJECTIVE OF THE INVENTION

An objective of the present invention is to provide a system for lifting and lowering of the accessories attached to an agricultural vehicle that does not require the presence of continuous pressure and thus avoids the generation of heat.

Another objective of the present invention is to provide a system for lifting and lowering of the accessories attached to an agricultural vehicle that does not require a dedicated oil source.

BRIEF DESCRIPTION OF DRAWING

Figure 1 shows an embodiment of the present invention in OFF state.
Figure 2 shows an embodiment of the present invention in ON state.
Figure 3 shows an alternate embodiment of the present invention in OFF state.
Figure 4 shows an alternate embodiment of the present invention in ON state.

DETAILED DESCRIPTION OF THE INVENTION

Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.

As illustrated in Figure 1, an embodiment of an e-lift system for an agricultural vehicle (100) comprises an actuator (108), a pressure maintenance valve (109), a directional control valve (110), a bypass valve (111), an oil return line (112) and a switch (not shown) for toggling the directional control valve (110). Said e-lift system (100) is adjunct to an existing power steering system that comprises an oil source (101), a hydraulic pump (103), a power source (102) for said hydraulic pump (103), a steering system (104) with an oil input port (105) and an oil return port (106) and a steering cylinder (107). The oil return port (106) of the power steering system is associated with the e-lift systems (100) and acts as an oil input port for the e-lift systems (100). The bypass valve (111), the actuator (108), the directional control valve (110) and the pressure maintenance valve (109) are connected between the oil output port (105) and the oil return line (112) one after the other and in parallel to each other as illustrated in Figure 1. The directional control valve (110) used is a solenoid valve. Preferably, the solenoid valve is a three port two position directional control valve. In an alternate embodiment as illustrated in Figure 3, the directional control valve (110) used is a two port two position directional control valve.

As illustrated in Figure 1 and Figure 3, if the switch is in OFF state, the directional control valve (110) is de-energised and thus the directional control valve (110) becomes open. Hence, the return hydraulic oil from the power steering system flows through the directional control valve directly to the oil source. Due to the opening of direction control valve (110), the pressure maintenance valve (109) does not open and hence there is no pressurized hydraulic oil to the actuator (108) and hence there is no action on the accessory connected to the agricultural vehicle.

As illustrated in Figure 2 and Figure 4, if the switch is in ON state, the directional control valve (110) is energised and thus the directional control valve (110) becomes closed. Hence, the return hydraulic oil from the power steering system will not flow through the directional control valve directly to the oil source. Due to closing of direction control valve (110), the pressure maintenance valve (109) opens and hence the pressurized hydraulic oil flows to the actuator (108) and thus lifts the accessory connected to the agricultural vehicle.

The e-lift system for an agricultural vehicle as disclosed in the present invention does not require any dedicated hydraulic oil source. That will receive the return oil from the hydraulic power steering system as its input. Further, the present system does not entail the availability of constant pressure within the system. The pressure is required only when the switch is ON and the system is in working state. If the switch is in OFF state, the oil flows back to the oil tank through the directional control valve with minimal flow restriction and this avoids continuous pressurized flow.

It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.

Though only a solenoid valve has been described for direction control, other forms of achieving direction control as is conventionally known in the state of the art, will also fall within the scope and purview of the present invention. Further, the disclosed system, in addition to being fitted on new agricultural vehicles may also be fitted on previously purchased tractors having power steering system as well (capable of being retrofitted).