FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
MEANS TO DISENGAGE HYDRAULIC PUMP FROM ENGINE
2. APPLICANT
MAHINDRA & MAHINDRA LTD.
1, GATEWAY BUILDING, APOLLO BUNDER, MUMBAI - 400001. AN INDIAN COMPANY.
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
The invention generally relates to a mechanical couplings means, and particularly, for engaging/disengaging engine power with hydraulic pump, which is generally run by engine power to actuate hydraulic system of vehicle, especially in the field of application vehicles / off-road vehicles such as tractors. More particularly, the invention relates to a coupling mechanism for disengagement of hydraulic pump from engine drive, whenever operation of hydraulic pump is not needed, thereby, to reduce undeserved horse power' drain on engine.
BACKGROUND ART
In vehicles, especially, application vehicles such as farm machineries like tractors; construction machineries like loaders, excavators; earth moving machineries / equipments which are primarily designed for specific purposes, applications are generally carried out by auxiliary power source such as hydraulic system which actuates the end attachments or implements (existing, in-built or add-on) of the vehicle. Fluid flow to this hydraulic system is generally actuated by hydraulic pump that is driven by engine and consumes significant amount of engine power while running. Generally, this hydraulic pump is continuously engaged with engine drive and hence runs continuously, whenever engine is running.
Whenever end application or implement is required to be actuated, operator has to operate / position the lever so that hydraulic pump generates flow to actuate hydraulic system which thereby powers the implement to move as per requirement. When end application is not

required, repositioning of lever cuts flow from hydraulic pump to hydraulic system, however, even then hydraulic pump remains engaged (rigidly) with engine drive and keeps running. This continuous running of hydraulic pump with no useful work / output (when end application is not required) results in loss of power, adversely affecting fuel consumption and also lowers life of hydraulic pump.
Hence, there exists need to separate hydraulic pump from primary power source such as engine drive, and which can also be engaged by operator as and when required, so that:
(i) Horse Power drain of primary power source (like engine) can
be reduced significantly, (ii) fuel economy can be improved, (iii) life of auxiliary system (including hydraulic pump) can be
improved, (iv) noise can be reduced (when auxiliary power source such as
hydraulic pump is not needed to be run).
The invention proposed herewith provides a means to conveniently achieve such separation / disengagement of auxiliary power source such as hydraulic pump which is drivingly engaged to primary power source such as engine drive.
Though proposed system is unique considering its mechanism configuration, some of the patent documents related to disengaging the auxiliary power source from primary power source are discussed hereunder as prior art..

EP patent 135790 titled "Accessory Drive Control Mechanism" discloses an accessory drive system for controlling operation of engine driven accessories that comprises a crank clutch operatively mounted to and rotated by engine having an output member which is decoupled from the engine in response to control signals in one operable state and which is coupled to and rotates with the engine during another operable state, and a two-speed accessory drive for driving engine accessories, including an input adapted to be driven by output member of crank clutch during the second operable state.
US Patent 20040118621 titled "Live Hydraulics for Utility Vehicles" discloses a hydraulic system which is coupled directly to torque converter of a vehicle, and drives a hydraulic pump that provides both continuous hydraulic fluid as a power source (for working implements such as a jack hammer or hydraulic chain saw) and intermittent hydraulic fluid as a power source (to raise and lower a snow plow blade, for example). A clutch is used to engage or disengage the hydraulics when desired.
As mentioned in above prior art, in typical hydraulic pump separation / disengagement method, in typical hydraulic pump application, clutch is mounted on input shaft of hydraulic pump. As clutch has an integral pulley, a belt or some other means is used as input-media to the clutch. Such belt or other means normally gets drive directly from engine. When there is no power to the clutch, the hydraulic pump does not engage; however, when power is supplied to the clutch, the hydraulic pump is engaged to provide hydraulic pressure.

In above mentioned system, generally, clutch is engaged by means of electromagnetic clutch system. Additional / separate power source is necessary to actuate electromagnetic clutch. Further, during operation, to keep the clutch in engaged position, power source has to deliver power continuously, hence, although electromagnetic system provides solution to the problem, it is not preferable as it essentially requires power source (i) to actuate engagement - disengagement mechanism and also (ii) throughout the operation of engagement.
Also, this system necessitates use of springs to put the clutch in disengaged position that further raises (production) costs. Also, clutch plates are prone to wear & tear and need to be replaced frequently thereby adding to maintenance / service activities and related costs.
Hence to obviate above mentioned problems, need does exist to provide a simple engage-disengage mechanism to separate auxiliary power source (like hydraulic pump) from primary power source (like an engine) that is easy to operate, low cost and which can be operated manually as well as through powered means.
SUMMARY OF THE INVENTION
Main object of the invention is to reduce horsepower drain of primary power source such as engine, thereby improve its fuel economy, by enabling and facilitating separation of occasionally used equipment(s) / machinery(ies), when not required, from primary power source such as engine drive.

Another object of the invention is to increase working life of occasionally used equipment(s) / machinery(ies) such as hydraulic pump by avoiding their undesirable idle running.
Yet another object of the invention is to provide a simple mechanism to separate occasionally used equipment(s) / machinery(ies) such as hydraulic pump, when not in use, from primary power source such as engine drive.
Yet another object of the invention is to separate auxiliary power source such as hydraulic pump from primary power source such as engine drive, so as to enable and facilitate maintenance of auxiliary power source such as hydraulic pump and hydraulic system even when primary power source such as engine is in running condition.
Yet another object of the invention is to provide a low cost and simple-in-operation mechanism, to separate auxiliary power source such as hydraulic system from primary power source such as engine drive.
Yet another object of the invention is to provide a mechanism to separate occasionally used equipment(s) / machinery(ies) that does not require any power source to actuate engage-disengage or to maintain the engaged or disengaged position.
Yet another object of the invention is to provide a mechanism which can be operated manually as well as with some power means or both as desired, to separate occasionally used equipment(s) / machinery(ies).

BRIEF DESCRIPTION OF THE DRAWINGS
The invention and further advantageous developments and arrangements of the invention will now be described and explained in more details by way of example and with reference to the accompanying drawings in which:
FIG.1 illustrates cross sectional view of declutching mechanism of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
Cross sectional view of coupling mechanism of the present invention is depicted in FIG.l. Coupling mechanism described herein, for separating hydraulic pump from engine drive, mainly comprises an auxiliary shaft 1, having one end, connected to engine drive (not shown) via a pinion gear 2 and the other end is operatively engaged with forward end of hydraulic pump input shaft 3 via another pinion 4. Towards hydraulic pump input shaft end of auxiliary input shaft 1, it has four provisions adapted to receive balls 14 into it. There are such four provisions in preferred embodiment; however, those skilled in the art will appreciate that such provisions can be in more or lesser numbers, as per design requirement. Further, again, towards hydraulic pump input shaft end of auxiliary input shaft 1, mounted there is a cam ring 5 on its outer periphery such that cam ring 5 is adapted to slide on auxiliary shaft 1. Cam ring 5 is provided with groove(s) 6 on outer periphery / diameter and has taper 7 on its inner periphery. Fork 8 at its lower end, rests in the groove 6 of cam ring 5 and at upper end is integral with a slider 9. Other end of the slider 9 is fastened with lower end of operating lever 10 and upper free end of this operating lever 10 that can be operated by operator manually or through some other means for engaging and disengaging the hydraulic

pump with engine drive. Also, operating lever 10, at mid way, is pivoted to cover plate at pivot point 11. Slider 9 is free to slide in circular provision, preferably circular cavity of cover plate. There is spring 12 and ball 13 arrangement to hold the slider 9 in either shifted position (engaged or disengaged).
As already described in earlier sections, generally, hydraulic pump is undetachably (/rigidly) connected with engine drive and hence remains in running condition along with running engine even when it is not required functionally. Mechanical De-clutching system of the present invention as disclosed herewith provides a mechanism to separate hydraulic pump from engine drive, to put the hydraulic pump off when not required, without having to stop the (running) engine.
When hydraulic pump is required to run to develop pressure to actuate hydraulic system of vehicle such as tractor, operator has just to pull the operating lever 10 in the direction as shown in FIG.l, to put hydraulic pump in engaged position with engine drive.
When operating lever 10 is positioned to right (RHS) (i.e. for engaging hydraulic pump with engine drive) as shown in FIG.l, its rotation about pivot point 11 makes slider 9 along with fork 8 to move in opposite direction that of operating lever 10. As fork 8 is integral with slider 9, fork 8 and slider ring 5 move in the same direction (towards hydraulic pump input shaft 3), thereby taper of slider ring 5 pushes the balls 14 inside slot on the pinion 4 forcing them to engage and power gets transferred from engine drive to pinion 2 and auxiliary input shaft 1 to slider 5 to balls 14 to another pinion 4 and input shaft 3 of hydraulic pump, thereby running hydraulic pump 15 to develop pressure to actuate hydraulic system of vehicle. There are four such

balls present in preferred embodiment, however, those skilled in the art will appreciate that there can be more or lesser number of balls as per design requirement.
To separate hydraulic pump from engine drive, operating lever 10 is moved and positioned to left (LHS) as shown in FIG.l, its rotation about pivot point 11 makes slider 9 along with fork 8 to move in opposite direction that of operating lever 10. As fork 8 is integral with slider 9, fork and slider ring 5 move in the same direction, thereby taper of slider ring 5 releases balls 4 making them fly out of slot on the pinion 4 under centrifugal force acting on them due to rotational motion of shafts, thereby cutting the power flow from auxiliary input shaft 1 to pinion 4. Thus running of hydraulic pump can be stopped without interference with regular operations of engine.
To hold Operating lever 10 in either shifted position (engaged or disengaged), there is spring ball arrangement on slider 9. A spring 12 is pressed against ball 13 and other side of the spring is restricted by a plug 16. There are two grooves 17 on the slider 9. The ball 13 fits into those grooves and restricts further movement of the slider and operating lever 10.
It will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.

We claim,
1) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive comprising:
an axillary shaft for operatively engaging engine drive with hydraulic pump;
an input shaft for transferring power from said axillary shaft to said hydraulic pump;
a first rotary engaging member for transferring power from engine to said axillary shaft;
a second rotary engaging member for transferring power from said axillary shaft to said input shaft;
a coupling member for operatively engaging said axillary shaft with said input shaft;
at least shifting means such as fork for selectively shifting said coupling means;
at least one sliding means such as shifting shaft for adaptively receiving said shifting means such as fork;
wherein
one end of said axillary shaft is adapted to receive a first rotary engaging member thereby to transfer engine power to hydraulic

pump and other end is designed in such a way to form like socket adapted to receive said second rotary engaging member,
wherein
said socket end of said axillary shaft is having provision for carrying engaging member, such as balls, to operatively engage with said second rotary engaging member by shifting said coupling member in engaged position direction.
2) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive according to claim 1, wherein said socket end of said axillary shaft is provided with plurality of provision for carrying said engaging means correspondingly.
3) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive according to claim 1, wherein said first rotary engaging member is a pinion gear.
4) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive according to claim 1, wherein outer periphery of said coupling member is provided with groove adapted to receive said shifting means such as fork end.
5) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive according to claim 1, wherein inner periphery of engaged position shifting end of said coupling

member is provided with tapered surface such as chamfer for smooth shifting.
6) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive comprising:
an auxiliary shaft for operatively engaging engine drive with
hydraulic pump;
an input shaft for transferring power from said axillary shaft to
said hydraulic pump;
a first rotary engaging member for transferring power from
engine to said axillary shaft;
a second rotary engaging member for transferring power from
said axillary shaft to said input shaft;
a coupling member for operatively engaging said axillary shaft
with said input shaft;
at least shifting means such as fork for selectively shifting said
coupling means;
at least one sliding means such as shifting shaft for adaptively
receiving said fork;
wherein
said shifting means such as fork is rigidly mounted on one end of said sliding means such as shifting shaft, that is provided with at feast one recess for engaging with a detent assembly so as to restrain/retain engaged position of said axillary shaft with said input shaft, and another end of said sliding means connected to an operating lever.

7) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive according to claim 1 & 6, wherein said detent assembly comprising a detent adapted to engage with said groove in said shifting shaft; a resilient member such as spring to urge said detent to engage with said recess in said shifting shaft as the operating lever shifts said sliding means such as shifting shaft in the engaged position; a retainer to hold said resilient member against force generated by said sliding means such as shifting shaft as it shift towards engaged position.
8) A coupling mechanism for engaging-disengaging auxiliary equipment such as hydraulic pump with pimary power source such as engine power drive according to claim 1 & 6, wherein said operating lever is pivoted with cover plate to move said sliding means such as shifting shaft.