FIELD OF INVENTION
This invention relates to a lift-o-matic/auto lift system for agricultural tractors.
BACKGROUND/PRIOR ART OF INVENTION;
The effective field capacity of machine is a function of the rated width of the machine, the percentage of rated width actually utilized, the speed of travel, and the amount of field time lost during the operations. The effective field capacity of a tractor is given by,
(Equation Removed)
Where,
C= Effective field capacity, (ha/h)
S= Speed of travel, (km/h)
W= Rated width of implement, (m)
Ef= Field efficiency (%)
In above factors, the lost time is most difficult variable to evaluate in relation to the field capacity. The field time may be lost as a result of adjusting or lubricating the machine, breakdown, clogging, turning at the ends, adding seed or fertilizer, unloading harvested products, waiting for crop transport equipment. Out of these, turns at headland or corners of the field represent
a loss of time that is often of considerable importance, especially for short fields. Time losses that tend to be proportional to area become increasingly important as the width or speed of an implement is increased, because they then account for a greater percentage of the decreased total time per hectare.
So the relative importance of interruptions proportional to area may be determined from the following equation,
(Equation Removed)

Where,
To = Theoretical time per hectare
Te = Effective operating time =To x K/100
K= Percentage of implement width actually utilized
Th = Time lost per hectare due to interruptions that are not proportional to area.
Ta = Time lost per hectare due to interruptions that tend to be proportional to area
From the above equations, it's clearly seen that, to increase the field efficiency of tractor, it's necessary to reduce the total time loss. Also to
maximize the economic performance of man-machine system, there is need to focus on man factor because once the reliability of machine is fixed, the reliability of man decides the performance of man-machine system. During the field operations, with tractors, turns at the ends or corners of a field represents a loss of time as well as drudgery to the tractor operator which ultimately reduces the field capacity of the machine. So, in that view lift-o-matic/auto lift system will help to maximize the comfort level of operator while operating the tractor in field and minimize the total operational cost of the tractor.
Turns at the ends or corners of a field represents a loss of time as well as drudgery to the tractor operator. Tractor operator is required to do many operations while turning. Lifting of the implement by the draft control lever is not a problem while turning, but lowering after the turning up to the previously set depth is the most tedious work, because the lock nut provided for the purpose loosens again and again due to frequent lifting/lowering of the implement. This also disturbs the depth and draft of operation. Hence, there is a need of an arrangement which can control the lifting and lowering of the implement during turning independently of position and draft control levers. Lift-o-matic/auto lift control is one such kind of arrangement. It is control, which can lift the implement up to the maximum in its one position and can lower it up to the previously set depth in the other position. So in this regard, it is the third control other than position and draft control which can control the lifting and lowering of the implement independently.
The condition can be fulfilled by designing such linkages which can directly operate the spool of direction control valve but problem arises when complete lifting takes place because after complete lifting, system should be neutral otherwise relief valve will blow which is not a good practise. Again to develop the separate linkages to bring the system in neutral condition shows the system more complicated. Therefore, it is required to develop simplified lift-o-matic/auto lift system.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a lift-o-matic/auto lift system for agricultural tractors which overcomes disadvantage (s) associated with the prior art(s).
Another object of the present invention is to provide a lift-o-matic/auto lift system for agricultural tractors which is simple in construction.
Further object of the present invention is to provide a lift-o-matic/auto lift system for agricultural tractors which is efficient.
STATEMENT OF INVENTION
According to this invention, there is provided a lift-o-matic/auto lift system for agricultural tractors comprising of a plurality of auto lift control linkages connected with a button assembly to actuate lever which operates hydraulic lift system.
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:
Figl shows: Lift-o-matic/auto lift system.
Fig. 2 & 3 shows: new auto lift control linkages connected to hydraulic lift system or auto lift control of the present invention.
Fig. 4 shows: auto lift control system integrated with hydraulic lift assembly.
Fig. 5 shows: lift-o-matic arrangement on system.
Fig. 6 shows: LOM linkages in hydraulic system.
Fig. 7 shows: step #1
Fig. 8 shows: step # 2
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:
The present invention discloses a lift-o-matic/auto lift system for agricultural tractors. Referring to fig. 1, wherein the system comprising of a link to actuate lever which operates hydraulic lift system. The link is operated by means of button assembly.
The button requires very less force to operate. Further, the button assembly is attached to two linkages so as to actuate the spool of the distributor.
In Auto lift control of the present invention, the new auto lift control linkages are added to existing hydraulic lift system (shown in fig. 2 8B 3). In auto lift control system, the actuation to hydraulic lift system is through button assembly connected with auto lift control linkages. Pressing the button
actuates the existing actuating lever (shown in fig. 3) through auto lift control linkages and in same respect the hydraulic lift actuates, lifting occurs. Again pressing the button lowers down the three point linkages system to its original position as set by the operator. So in this regards, this system ensures the constant depth and draft of operation.
Further, reference may be made to fig. 4 indicating integration of auto lift control system with hydraulic lift assembly.
The system of the present invention comprising of a plurality of linkages as shown in figure 5-8 working in combination.
Linkage Operation Process
Cycle of Lifting
1. Lifting of implement at the end of field requires pressing of Auto-Lift Button 'A'.
2. Actuation of button generates rotational motion in the linkage B.
3. Linkage C is combination of atleast two levers 8B one rotational member which wholly get attached to linkage B.
4. A Rotational Motion in Link B further gets transmitted in Linkage C and hence linkage C presses point D (existing lift point) in forward direction, which actuates spool in linear motion from rotational feedback.
5. With actuation of spool, hydraulic circuit gets activated 8B oil enters in
hydraulic cylinder and lifting of implement takes place.
6. At the end of stroke, piston comes backward 8B hits linkage E, which
automatically pulls the spool backward. As a result, system gets
neutral 8B cycle of lifting completes.
Cycle of Dropping
1. With pressing of Auto Lift Button 'A' in opposite direction, cycle of dropping starts.
2. This actuation resets rotational motion in linkage B.
3. Simultaneously, link C is pulled backward releasing force on point D, which in turn pulls spool backward & starts dumping of oil in sump in turn dropping of implement.
4. All the linkages come in its original position already set in the lift to work it normally or at pre-desired and preset setting.
It is more comfortable for the operator during turning to operate the button which requires very less force because it is the kind of quick lift/lower control which gives quick response to the implement for lifting the implement, and hence the process is more faster than original or existing process of lifting implement with help of levers. It also ensures accurate depth and draft operation in position and draft control mode because there is no need to disturb position and draft control lever repeatedly during turning (which generally gets affected with manual use 8B reset of control lever.)
Advantages of the Lift-o-matic/auto lift Control
o Comfortable add to the tractor operator at the time of turning/ operating the tractor in field.
o Reduces operator energy expenditure/fatigue per turn.
o Ensures constant depth and draft of operation during cultivation.
o Farmer doesn't have to fiddle with hydraulic lever system at each time. (Just required to set lever position during the starting of field operation).
o As an override system, the sensing of hydraulic system won't affect.
o No major change required introducing this system on tractor.
o As a linkage operation is parameter of time in overall field operation, a qualitative time is being saved 8B hence improvement in the overall field efficiency. (Refer Equation-2)
The linkage of the present invention for getting the system neutral avoids requirement of separate linkages to bring the system neutral.
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. A lift-o-matic/auto lift system for agricultural tractors comprising of a
plurality of auto lift control linkages connected with a button
assembly to actuate lever which operates hydraulic lift system.
2. A lift-o-matic/auto lift system as claimed in claim 1, wherein said plurality of linkages comprising of linkage C attached to linkage B.
3. A lift-o-matic/auto lift system as claimed in claim 1 or 2, wherein said linkage C is combination of atleast two levers and one rotational member.
4. A lift-o-matic/auto lift system as claimed in any of the preceding
claims, wherein the linkage for getting the system neutral avoids
requirement of separate linkages to bring the system neutral.
5. A lift-o-matic/auto lift system for agricultural tractors substantially as
herein described with reference to the accompanying drawings.