SYSTEM FOR ENGAGEMENT/DISENGAGEMENT OF HYDRAULIC LIFT
PUMP FROM ENGINE DRIVE
FIELD OF INVENTION
The present invention relates to a system for engaging and disengaging a hydraulic lift pump from engine drive of a vehicle.
BACKGROUND
Generally, a hydraulic lift is operated through pressurized oil. The oil is pressurized by a hydraulic gear pump that is driven by a hydraulic pump driving shaft connected in series with the timing gear of an engine. Conventionally, a hydraulic lift pump is driven by the engine directly by a fixed drive coupling. This leads to the operation of the hydraulic lift pump at all the times during running of the engine. The pressurized oil is supplied to the control/composite valve through a gear pump, which operates a ram cylinder. The piston in the cylinder moves and consequently rotates the rockshaft over which the lift arms are attached.
At the time when the hydraulic lift operation is not required, the hydraulic lift pump mounted on the engine is continuously running and discharging oil from a reservoir (differential). The oil discharged form the reservoir is circulated back to the reservoir through a backpressure valve. This continuous running of the hydraulic lift pump not only reduces the life of various components of the hydraulic lift pump but also consumes extra power leading to more fuel consumption, thereby leading to reduced fuel efficiency.
Thus, there is a need for a mechanism that disengages the hydraulic lift pump from the engine drive when not in use.

OBJECT AND SUMMARY OF INVENTION:
The object of the present disclosure is to provide a mechanical system between the engine drive and hydraulic lift pump for engaging/disengaging the hydraulic pump from the engine drive, thereby reducing the power consumption by a hydraulic lift pump and enhancing the fuel efficiency.
Another object of the present disclosure is to enhance the life cycle of the hydraulic lift pump.
Yet another object of the present disclosure is to provide the easy approachability for operating the present system.
The present invention relates to a hydraulic pump-driving system that uses a coupling mechanism to engage or disengage the hydraulic pump from engine timing gear drive according to the requirement of hydraulic lift. This results in the saving of engine power and consequently reduces fuel consumption. The link mechanism is provided for its operation i.e. to engage/disengage the hydraulic lift pump from the engine. The link mechanism reaches the driver seat for actuation/de-actuation. The driver is able to operate it from his seat. The engaging of hydraulic pump only at the time of need decreases the wear & tear of pump parts, which consequently increase the life of pump.
Further, the driver can disengage the pump when it is not required for the task that he is carrying out. For example, when the tractor is operating on haulage operation, there is no need of lift operation. At that time, the hydraulic lift pump can be disengaged, which saves the power of engine and consequently the fuel consumption of the vehicle. Similarly, there are other field operations also in which hydraulic pump is not required, like generator application, thresher application, reaper application, etc.
The present system has a small and compact design which is adjusted between the engine block and hydraulic lift pump of the vehicle, more particularly in a tractor.

Accordingly, the present disclosure provides a system for engaging and disengaging the hydraulic lift pump from engine drive of a vehicle consisting of a shifting mechanism comprising:
a hydraulic pump-driving shaft fitted in the engine gear train of the vehicle
and a movable coupling sleeve with internal and/or external splines
disposed on hydraulic pump splines in such a way that in the forward
direction, the jaws of the coupling sleeve matches with the driving shaft
jaws and actuates the engine, whereas, in the reverse direction, the
coupling sleeve disengages the pump from driving shaft and remains
stable,
housing for said shifting mechanism coupled to the hydraulic pump with
coupling sleeve;
a shifter lever sub-assembly coupled to said shifting mechanism housing.
Brief description of the invention:
Figure 1 illustrates an improved hydraulic driving shaft, according to the preferred embodiment of the present disclosure.
Figure 2 shows the movable coupling sleeve, according to the preferred embodiment of the present disclosure.
Figure 3 shows the shifting mechanism housing, according to the preferred embodiment of the present disclosure.
Figure 4 shows the shifter lever sub assembly, according to the preferred embodiment of the present disclosure.
Figure 5 shows the shifting mechanism assembly, according to the preferred embodiment of the present disclosure.

Figure 6 shows the link rod assembly, according to the preferred embodiment of the present disclosure.
Figure 7 shows the disengaged position of the hydraulic pump.
Figure 8 shows the engaged position of the hydraulic pump.
DETAILED DESCRIPTION:
The embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments. The present disclosure can be modified in various forms. The embodiments of the present disclosure described herein are only provided to explain more clearly the present invention to the ordinarily skilled in the art of the present invention. In the accompanying drawings, like reference numerals are used to indicate like components.
Fig. 1 illustrates a modified hydraulic pump driving shaft, wherein jaws (10) are provided at the head of said hydraulic pump driving shaft. The hydraulic pump driving shaft is fitted in the engine gear train of the vehicle. This hydraulic pump-driving shaft takes power from gear train and drives the hydraulic pump.
A movable coupling sleeve, as shown in Fig. 2 is disposed on hydraulic pump splines. The coupling sleeve with internal and/or external splines (20) moves on the hydraulic pump splines and helps in engaging or disengaging the pump from driving shaft. In the forward direction, the jaws of the coupling sleeve (30) matches with the driving shaft jaws (10) and come into working condition. In the reverse direction, the coupling sleeve disengages the pump from driving shaft and remains stable.

Figure 3 shows the housing of the shifting mechanism, which is fitted on the hydraulic pump with coupling sleeve. The housing conies between pump and the crankcase. The pump and housing are coupled with the crankcase with the help of bolts & washers.
Figure 4 shows the shifter lever sub assembly, which is coupled to said shifting mechanism housing.
The said shifter lever sub-assembly comprises the sleeve-shifting lever (3), which is coupled to the shifter lever bracket (2) and actuation lever (1).
The sleeve-shifting lever (3) is locked with shifter lever bracket (2) with the help of spring loaded ball assembly, so that the ball can take seat in the cavity made on shifting lever. The actuation lever (1) is coupled to the sleeve shifting lever (3) with the help of spring cotter sleeve.
Figure 5 illustrates the shifter lever sub-assembly (5) assembled on the shifting mechanism housing (4) by providing gasket between them in such a way that the pin of shifting lever attains its position in the groove of coupling sleeve (6). This is achieved by rotating said shifter lever sub-assembly (5) on the housing (4). After the sub-assembly (5) is settled on said housing (4), tight it with the help of bolts and washers.
The actuation lever (1), assembled with a link rod is connected to the knob assembly which is fitted on the vehicle to enable the operator to engage or disengage the system.
The link rod may be assembled with the actuation lever (1) with the help of coupler pin & split pin.
Figure 6 shows the knob assembly connected to the link rod in engaged and disengaged position of the hydraulic pump from the engine drive.

The said link mechanism is assembled on the housing to engage/disengage the hydraulic lift pump from the engine. The link mechanism may reach the driver seat for actuation/de-actuation. The driver is able to operate it from his seat. The engaging of hydraulic pump only at the time of need decreases the wear & tear of pump parts, which consequently increase the life of pump.
Working:
The operator engages or disengages the system by simple pushing or releasing the knob. The knob is pushed to engage the hydraulic pump with the engine and is pulled to disengage the pump from the engine. Figure 8 shows the engaged position of the hydraulic pump.
When knob assembly is pulled (for disengaging hydraulic pump purposely), it actuates the actuation lever assembly, which slides the coupling sleeve in the backward direction on hydraulic pump shaft splines. During this movement, hydraulic lift pump working stops (disengaged from engine drive). The hydraulic pump comes into the stationary position and hydraulic oil stops circulating in the system circuit, which consequently stops the hydraulic lift working. Figure 7 shows the disengaged position of the hydraulic pump.
The various embodiments of the invention may be developed to enable the system to operate electronically or automatically.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.

We claim:
1. A system for engaging and disengaging the hydraulic lift pump from engine drive
of a vehicle consisting of a shifting mechanism comprising:
a hydraulic pump-driving shaft fitted in the engine gear train of the vehicle
and a movable coupling sleeve with internal and/or external splines
disposed on hydraulic pump splines in such a way that in the forward
direction, the jaws of the coupling sleeve matches with the driving shaft
jaws and actuates the hydraulic pump, whereas, in the reverse direction,
the coupling sleeve disengages the pump from driving shaft and remains
stable,
housing for said shifting mechanism coupled to the hydraulic pump with
coupling sleeve;
a shifter lever sub-assembly coupled to said shifting mechanism housing.
2. The system as claimed in claim 1, wherein said shifting mechanism is provided between the engine block and the hydraulic lift pump of the vehicle.
3. The system as claimed in claim 1, wherein a shifter lever sub-assembly is coupled to the shifting mechanism housing by providing gasket between them in such a way that the pin of shifting lever attains its position in the groove of coupling sleeve.
4. The system as claimed in claim 1, wherein the shifter lever sub-assembly comprising:
sleeve-shifting lever coupled to the shifter lever bracket;
actuation lever connected to sleeve-shifting lever with the help of spring
cotter sleeve.
5. The system as claimed in claim 4, wherein the sleeve-shifting lever is locked with
shifter lever bracket with the help of spring loaded ball assembly, which is
provided such that the ball locks the shifting lever in bracket by resting in its cavity made on said shifting lever.
6. The system as claimed in claim 1, wherein a link mechanism connected to said shifting mechanism is provided to enable the operator to engage/disengage the hydraulic lift pump from the engine drive.
7. The system as claimed in claim 6, wherein the link mechanism comprising:
a link rod connected to said lever sub-assembly and a knob assembly, which is fitted on the vehicle to enable the operator to engage or disengage the system.
8. A process of engaging and disengaging the hydraulic lift pump from engine drive by employing the system as claimed in the preceding claims.
9. The system for engaging and disengaging the hydraulic lift pump from engine drive substantially as herein described with reference to the accompanying drawings.
10. The process for engaging and disengaging the hydraulic lift pump from engine drive substantially as herein described with reference to the accompanying drawings.