FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
AND
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and ruleI3)
1. TITLE OF THE INVENTION:
"MEANS FOR ADJUSTING OPERATING FORCE FOR AN OPERATOR
LEVER"
2. APPLICANT:
(a) NAME: MAHINDRA & MAHINDRA LTD.
(b)NATIONALITY: Indian Company incorporated under the Companies Act, 1956
(c) ADDRESS: Gateway Building, Apollo Bender, Mumbai - 400001, Maharashtra, India,
3. PREAMBLE TO THE DESCRIPTION:
The following specification describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION:
The present invention generally relates to an operating [ever, and particularly relates to an operating effort/force adjusting means incorporated with the operating lever for adjusting the lever operating effort in accordance with the comfort level of individual operator.
BACKGROUND OF THE INVENTION:
In mechanical system, conventionally, operating lever is directly connected to a system which is to be actuated or operated, and the manual effort required to operate the iever (thereby the system) mainly depends on the construction and configuration / complexity of the system. Hence, to reduce operating effort of the system, the whole system needs to be constructed accordingly without affecting basic essential reliability and durability of the system. This may further lead to complex design and complex manufacturing of the system. So in mechanical system, by default, some amount of effort will be required for actuating system which is not adjustable, and if at all, an operating force control means is to be provided, then the force adjustment will be over and above the effort required to operate the system. At the same time, the manual effort required for operating an operating lever incorporated with electronic control system is very negligible compare with mechanical system due to simplicity of the construction of electronic devices and configuration of the electronic system. In this case, an operating force control means is to be interposed with the operating lever to increase or decrease the operating effort according to the requirement of the system due to high sensitivity of the electronic devices in accordance with the operator comfort.
The present invention is mainly intended for applications in the field of off road vehicles such as tractors; however, the preferred embodiment of the present invention may be adapted with other operating levers without departing from the scope of the present invention. Generally, tractors are formed with hydraulic system for operating earth moving implements. In which, two parameters are to be set before starting field operation. One is position of the implement with respect to soil surface and another is draft of the implement for smooth operation and equal depth of soil preparation. Conventionally, separate control levers are provided in a single quadrant for setting these parameters. According to the present invention, the operating lever is being developed for combining operation of both position control (PC) & draft control (DC) in single lever and also

intended to adapt the present invention in tractor where it does incorporate electro hydraulic system for operating the implements. Since, draft and position of the implements are the critical parameters to be set and are being controlled by electro hydraulic system, it is preferable to incorporate an operating force control means to operate the lever at desired effort in accordance with the operator comfort.
There have been inventions in the field of gear shifting lever, typewriter keyboard and other operating lever for adjusting the effort required to operate respective system. There are different means such as mechanical control system through spring actuation, electronic actuation system and hydraulic actuation systems by which the operating effort of the lever may be controlled. Some of them are being described hereunder for reference:
Republic of Korea Patent 2003016662 discloses a device for controlling operating force of gear shift lever for maintaining a steady operation by detecting operation time of a gear shift lever, inferring the degree of the operating force and raising or lowering the operating force. The device is composed of an operating force detecting device, an adjusting device and an operating force adjusting device. The operating force detecting device has a strain gauge detecting an operation time from a strain ratio of tension or pressure of the operation pressed to a gear shift lever. The adjusting device raises or lowers the operating force by comparing a detected value and a reference value. The operating force adjusting device is mounted to the gear shift lever. The adjusting device adjusts the operating force to rotate the gear shift lever by adjusting a preload of a detent spring.
EP patent 821299 discloses an operational reaction force control device for an operating lever of a working machine. By which operation for effectively preventing the swing of load is made possible by imparting to an operating lever an operational reaction force that becomes greater as acceleration detected by an acceleration detecting means becomes greater, and moreover the operator can be relieved of fatigue. The devices comprises acceleration detecting means for detecting an acceleration of the working machine; and operational reaction force imparting means for imparting to the operating lever the operational reaction force that becomes greater as the acceleration detected by the acceleration detecting means becomes greater.

All the aforesaid prior inventions might have worked satisfactorily in accordance with the intention with which they developed; however, they have had drawbacks such as complexity of the system in terms design and manufacturing, more number of parts, complex control system and very expensive system to develop. Hence, there was need remains to develop an operating force control means which is capable of adjusting the operating effort as per operator comfort at low cost with less complexity and also to develop adjusting means which is easy to operate.
OBJECTIVE OF THE INVENTION:
The present invention overcomes the shortcomings associated with the prior art and achieves other advantages not realized by the prior art.
The main object of the present invention is to provide an operating force controlling means incorporated with an operating lever for adjusting manual effort required to operate the lever.
Another object of the present invention is to develop spring loaded adjusting means thereby to provide simple and cost effective operating force controlling means.
Yet another object of the present invention is to develop an operating force controlling means which is interposed/unified with an operating lever for use with operation of electronic control system.
Yet another object of the present invention is to develop an operating force controlling means incorporated with operating lever so as to enable safe and secure routing of the electrical connections conveniently through the lever, that are needed for actuating electro hydraulic control system.
Yet another object of the present invention is to develop operating force controlling means which is cost effective, less complex / simple and easy to adjust.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS:
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is longitudinal section view, illustrating preferred embodiment of the present invention.
DETAD1ED DESCRIPTION OF THE PREFERREI) EMBODIMENT:
In accordance with one aspect of the present invention, the operating force controlling means incorporated with an operating lever comprises an effort adjusting means. The operating force controlling means further comprises a tase and a first mounting member for receiving the operating lever mounting and the effort adjusting means for operatively integrating them with the help of an output shaft. The effort adjusting means further comprises a handle, a locking member, a shaft having variable diameter sections, a sliding member and a compression spring. The operating lever is mounted on a second mounting means which is operatively and relatively made integrated with the output shaft via a pin. The case is made of a thick wall for supporting the effort adjusting means via said variable diameter shaft. The shaft is provided with variable diameter section adaptably receiving the handle at outer end thereof, the locking member, the sliding member and the compression spring. The compression spring is disposed between the sliding member and the second mounting means so that by adjusting the forward and backward movement of the sliding member, the force exerted on the second mounting means shall be varied thereby the effort required for operating the lever can be adjusted as per operator comfort.

While this invention is susceptible of embodiments in many different forms, the drawings shown here and description of preferred embodiment are to be considered as an example of the principles of the invention and not intended to limit the invention to the specific embodiment shown and described. In the description below, reference numerals are used to describe the parts in the section view of FIG. 1.
Referring to FIG. 1, operating force controlling means according to the present invention is designated as 1 and other related parts are indicated with numerals for detailed description of the present invention with referring to corresponding numerals. The operating force controlling means 1 comprises an effort adjusting means 2 operatively incorporated with mounting end of an operating lever 7. The effort adjusting means 2 and mounting of the operating lever 7 are enclosed in a case 28 and further, the effort adjusting means 2 is being supported on a substantially thick wall 20. The thick wall 20 also gives rigidity to the construction of operating force controlling means and also restraints required movement of the operating lever 7. A base plate 5 is horizontally mounted on the wall 20 inside the case 28 for supporting the effort adjusting means 2. The base plate 5 is formed with a first mounting member 3, to which both effort adjusting means 2 and mounting of the operating lever 7 are operably connected via an output shaft 4. top surface of the base plate (5) is adapted to mate with bottom peripheral surface of said sliding member (13);The output shaft 4 is formed with a shank portion 22 and a circular head 21 adapted to pass through a through hole provided on the first mounting member 3. The shank portion 22 is also formed with a through hole 10 laterally.
The operating lever? consists of 90° elbow 26, upper end 29 and lower end 30.The upper end 29 is extended substantially upward as per operator comfort and to receive a handle (not shown). The lower end 30 is mounted on a second mounting member 6 which is disposed inside the case 28 and provided with a through whole adapted to receive the output shaft 4. The second mounting member 6 is made from a thick metal part having formed with oval shape. A through hole 25 is also provided with the second mounting member 6 adapted to connect lower end 30 of the operating fever 7 as well as for passing electrical wire means therethrough for actuating electro hydraulic system. The second mounting member 6 is also provided with a hole perpendicular to central axis thereof.

The adjusting means 2 comprises a handle 19, a shaft 17, a sliding member 13, a locking member 16, a compression spring 11 and a plain washer (not shown). The shaft 17 is formed with first diameter section 12 adapted to threadingly receive the sliding member 13, a second diameter section 14 for slideably and rotatably receiving through the wall 20 and a third diameter section 15 for threadingly receiving the locking member 16, and for receiving the handle 19. Outer peripheral surface of diameter section 12 of the shaft 17 is provided with threading and provided with a bore 31 adapted to receive the sliding member 13 and free end of the output shaft 4 respectively. Diameter section 14 of the shaft 17 is being designed for supporting with the thick wall 20 and diameter section 15 is being designed for receiving the locking member 16 for restricting axial movement of the shaft 17 with the help of a collar 32 provided on the diameter section 12. The outer end of the shaft 17 is provided with a pin inserting arrangement 18 for removably connecting the handle 19. The sliding member 13 is formed with a through bore and therein provided with internal threading adapted to engage with the diameter section 12 thereby for slidably moving along the length of the diameter section 12. The sliding member 13 is made of square shape for sliding over the surface of the base plate 5. The compression spring 11 having inner diameter sufficiently larger than the outer diameter of the diameter section 12 is disposed between the sliding member 13 and the second mounting member 6 and both ends of the spring is hold in circular slots 24 and 23 provided in the sliding member 13 and the second mounting member 6, respectively. A friction washer 27 is disposed between the first mounting member 3 and the second mounting member 6. The plain washer is disposed in the slot 23 for avoiding torsional twisting of the compression spring 11 when the operating lever 7 is getting operated.
The method of adjusting the force controlling means is illustrated in detail with referring to FIG.l. When the handle 19 is rotated in clockwise direction along with the shaft 17 about central axis thereof, the sliding member 13 moves forward along the axial length of the diameter section 12 and compresses the compression spring 11 to increase the force applied on the second mounting 6. This proportionately increases the effort required for operating the lever 7. When the shaft rotates in anticlockwise direction, the sliding member 13 moves backward and release the strain energy stored in the spring 11 thereby the effort required for operating the lever 7 can be reduced. Thus, as per the comfort level of operator, the effort for operating the operator lever can be adjusted.

We Claim.
1) An operating force controlling means (I) incorporated with an operator lever(7) for adjusting manual effort required to shift the lever, the force controlling means comprising:
an effort adjusting means (2) operatively associated with mounting end of the operator lever(7), said adjusting means comprising a shaft (17), one end of said shaft (17) is adapted to receive a handle (19) and other end is adapted to threadingly receive a sliding member (13), said effort adjusting means(2) further comprising a compression spring (II) that is being disposed between the sliding member (13) and a second mounting member (6), said second mounting member is rigidly connected with the operator lever (7);
a substantially thick wall (20) for removably supporting said effort adjusting means (2) via said shaft (17);
a base plate (5) horizontally mounted with the wall (20) and having integrated with a first mounting member (3) for rotatably and operatively connecting the mounting end of the operator lever(7) via an output shaft (4), top surface of the base plate (5) adapted to mate with bottom peripheral surface of said sliding member (13);
and
at least one friction washer (2?) is disposed between the first mounting member (3) and the second mounting member (6) to effect frictional engagement of the operating lever with the first mounting member (3) thereby retaining the shifting position thereof.
2) The operating force controlling means as claimed in claim 1 further comprising a case (28) for enclosing said effort adjusting means (2), the base plate (5) and the second mounting member (6).

3) The operating force controlling means as claimed in claim 1 wherein, said output shaft (4) comprises a shank portion (22) and a head (21) adapted to receive through the first mounting member (3) and is rotatably mounted with the first mounting member (3).
4) The operating force controlling means as claimed in claim 1 wherein, the second mounting member (6), formed of oval periphery in cross section and provided with substantial thickness, is adapted to receive the output shaft (4) and positively engaged therewith via a pin (10).
5) The operating force controlling means as claimed in claim 4 wherein, surface of said second mounting member (6) facing the adjusting means (2) is provided with a slot (23) adapted to receive a plain washer and one end of said compression spring (11) thereon so as to obviate twisting moment thereof.
6) The operating force controlling means as claimed in claim I and claim 5 wherein, surface of said sliding member (13) facing the second mounting member (6) is provided with a slot (24) adapted to receive a plain washer and other end of said compression spring (11) thereon so as to obviate twisting moment thereof.
7) The operating force controlling means as claimed in claim 1 wherein, said shaft (17) is formed with a first diameter section (12) for threadingly receiving said sliding member (13), a second diameter section 14 for slideably and rotatably receiving through the wall (20) and a third diameter section (15) for threadingly receiving a locking member (16).
8) The operating force controlling means as claimed in claim I wherein, the other end of the shaft (17) is provide with a bore (31) to receive free end of the output shaft (4) so as to give constructional stability and rigidity to the operating force controlling means (1).
9) The operating force controlling means as claimed in claim 1 wherein, the operator lever (7) is made of hollow tube and rigidly connected with a through hole (25)

provided in the second mounting member (6) to access wires for adapting said operating force control means (1) for electronic system.
10) The operating force controlling means as claimed in claim 1 wherein, one end of operating lever(7) is substantially extended and adapted to receive a handle(8) for comfortably operating the lever (7) and other end is positively connected with the second mounting member (6).
1 l)The operating force controlling means as claimed in claim 1 wherein, said shaft (17) comprising:
said first diameter section (12) for threadingly receiving said sliding member (13) which exerts pressure on the second mounting member (6) through said compression spring (11) by rotating the handle (19) in clockwise direction and to release the strain energy stored in the compression spring (11) by rotating the handle (19) in anticlockwise direction;
said second diameter section 14 for slideably and rotatably receiving through the wall (20);
and
said third diameter section (15) for threadingly receiving a locking member (16) and restricting axial movement of said shaft (17) by threadingly tightening the locking member (16) against a collar (32) provided in the first diameter section (12).