FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
TITLE OF THE INVENTION "ROCKER ARM ASSEMBLY"
The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.

Technical Field:
[001] The present invention relates to rocker arm assembly in an internal combustion engine. More particularly, the present invention relates to rocker arm made by forming of sheet metal and the lubrication system therein.
Background of the Invention:
[002] Rocker arms are as old as internal combustion engines. Over the years Rocker arms have been optimized in its design and material for better Performance, Durability, toughness, high dimension stability, Wear resistance, Strength and Cost of materials as well as economic factors are the reasons for optimization of rocker arm.
[003] The rocker arm is an oscillating lever that conveys radial movement from the cam lobe into linear movement at the poppet valve to open it. One end is raised and lowered by a rotating lobe of the camshaft via a tappet (lifter) and pushrod while the other end acts on the valve stem. When the camshaft lobe raises the outside of the arm, the inside presses down on the valve stem, opening the valve. When the outside of the arm is permitted to return due to the camshafts rotation, the inside rises, allowing the valve spring to close the valve.

[004] Traditional rocker arms utilized in valve trains of internal combustion engines are generally manufactured as forgings or casts. Forging and casting leads to heavy weight of the product. However, as revolution and output power of the internal combustion engines are increasing in recent years, there has been an increasing desire for inertial-weight saving. Therefore, there arises the need of providing rocker arm which is light in weight but equally compliant as far as its mechanical properties are concerned.
[005] Further, the lubrication of rocker arm is an important parameter during its working. There are various arts available on lubricating the rocker arm, but each of the arts is having its own merits and demerits.
[006] Lubrication of a rocker arm assembly can be by means of an oil mist generated within an engine housing. The oil mist coats engine components lubricating any surfaces of contact between them. The mist may not reach into the upper regions of the housing below the engine cover. This can result in metal to metal contacts at both ends of the rocker arms remaining dry leading to excessive wear and the need for frequent readjustment and replacement of parts. One of the solutions to this problem has been to drill oil channels laterally through the bosses of the rocker arms. The channels each communicate at first end with an oil

supply passage in the rocker arm support shaft, which normally provides a supply of oil to lubricate rocker arm bushes, and each exit at second end at appropriate points on the rocker arm bodies to supply oil to the push rod ball joints and rocker arm ends contacting valve stem assemblies.
[007] But this is quite expensive solution since the rocker arms are often formed of cast or forged metal and drilling of this material is difficult, particularly bearing in mind the narrow diameters of the drilled channels compared to their relatively long lengths. Therefore, there is unmet need to provide an improved lubrication system for the rocker arm assembly.
Objects of the Present Invention: __
[008] The main object of the present invention is to provide rocker arm assembly with lubrication system.
[009] Another object of the present invention is to provide rocker arm assembly with lubrication system wherein the said rocker arm is made from sheet metal by forming process.
[0010] Still another object of the present invention is to provide rocker arm assembly with lubrication system wherein the said rocker arm

assembly is light is weight and compliant to the desired mechanical properties.
[0011] Still further object of the present invention is to provide rocker arm assembly with lubrication system wherein the said lubrication system imparts accuracy thereby reducing the wastage of lubricating oil.
[0012] Still further object of the present invention is to provide rocker arm assembly with lubrication system wherein rocker body of the rocker arm assembly acts as the deflector for oil to be reached at the contact points.
[0013] Yet, the object of the present invention is to provide rocker arm assembly with lubrication system wherein no external passage/s is/are required for lubrication thereby minimizing the manufacturing operations and the cost of manufacturing.
[0014] Yet another object of the present invention is to provide rocker arm assembly with lubrication system which is inexpensive, reliable and light in weight.

Brief Description of the Drawings:
[0015] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiment/s herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein
[0016] Fig. 1 discloses the perspective view of the rocker arm assembly in accordance with the present invention.
[0017] Fig. 2 discloses the fragmentary view of the rocker arm body, contact pad, bushing and nut.
[0018] Fig. 3 shows the perspective view of another embodiment of rocker arm assembly with roller for valve contact point.
[0019] Fig. 4 shows fragmentary view of rocker arm body, roller, bushing, and nut as per the second embodiment of the rocker arm assembly.
[0020] Fig. 5 describes the profile of lubrication oil path in accordance with the present invention.

[0021] Fig. 6(a), 6(b) and 6(c) discloses two-hole lubrication, water packet with a hole (arbitrary shape) and annular grooves, respectively, on the bushing of the rocker arm assembly.
Detailed Description of the Present Invention:
[0022] Referring to Fig. 1, rocker arm assembly (20) comprises of rocker arm body (1), bushing (4), integrated profile (7) for contact point at valve end, contact pad (9), nut (3), and valve end tip (8); wherein the rocker body (1) is having fulcrum profile (2) at its center level and it houses the bushing (4); wherein the said busing (4) is having lubrication hole (5) and is fitted in the fulcrum profile (2) of the rocker arm body (1) by suitable means. The nut (3) is for holding the screw and also is a very essential component for tappet setting. The suitable means of fitting the bushing (4) in the fulcrum profile (2) are from riveting, screwing, metallic adhesion, threaded bush, structural cementing, caulking, etc., either taken individually or combination of thereof. The other end of the rocker arm body is provided with crimped edges (6), wherein the said crimped edges (6) accommodates the nut (3) for its seating. Valve end tip (8) houses the contact pad (9) wherein the said contact pad (9) is an alternative option to valve end tip (8) for its smooth functioning. The contact pad (9) is an alternative for curved sheet metal profile and also it would have a

damping property while making contact with the valve stem, thus reducing the wear and tear.
[0023] Referring to Fig. 3, which is another embodiment of the present invention comprises of rocker arm body (1), bushing (4), integrated profile (7) for contact point at valve end, roller (10), nut (3), and valve end tip (8); wherein the rocker body (1) is having fulcrum profile (2) at its center level and it houses the bushing (4); wherein the said busing (4) is having lubrication hole (5) and is fitted in the fulcrum profile (2) of the rocker arm body (1) by suitable means. The roller (10) is to achieve the reduced friction and wear and tear. The knife-edge rocker slides over the end of the valve stem putting a considerable amount of side pressure on the stem. This creates friction and wears the stem and guide. The rolling element of the roller rolls over the end of the valve stem. This eliminates the side load on the stem and greatly reduces the wear and tear, thus enhancing the valve guide life. Also it imparts larger scope for increasing the valve lift and rocker ratio. The suitable means of fitting the bushing (4) in the fulcrum profile (2) are from riveting, screwing, metallic adhesion, threaded bush, structural cementing, caulking, etc., either taken individually or combination of thereof. The other end of the rocker arm body is provided with crimped edges (6), wherein the said crimped edges (6) accommodates the nut (3) for its seating/joinery (11). The seating /joinery (11) of the nut (3) in the crimped edges (6) is achieved from the

press fitting, shrink fitting, welding, brazing, metallic adhesion, folding, structural cementing, etc.; either taken individually or combination of thereof.
[0024] Referring to Fig. 6(a), 6(b), 6(c), which shows the embodiments of the bushing with different lubrication means, wherein the said lubrication means are from two-hole lubrication (Fig. 6a), water packet with hole (Fig. 6b), annular grooves (Fig. 6c), either taken individually or combination thereof for better lubrication efficiency.
[0025] Rocker arm body (1) of the rocker arm assembly (20) of the present invention is made from unitary sheet metal providing much more strength per unit of weight and is characterized by an integral lubrication passage (12); wherein the profile of the lubrication passage is in such way that it provides added accuracy to lubrication and also minimizes the wastage of the lubricant. The lubrication passageway is an integrated passage way starting from the bush hole, the jet impinges on to the rocker body and flows to the contact points. The rocker arm acts as the deflector for oil. Due to such profile of the lubrication passage inside rocker body, no external passages (vertical riser and longitudinal passageways) are required which lead to elimination of additional manufacturing operations required therefor, and thereby reduces the cost of manufacturing.

[0026] An oil passage starts with a hole on the bushing, which is made either by drilling or piercing the bushing at the upper body end of the rocker arm. Oil from the rocker shaft enters the groove in the bushing of rocker arm and the pressurized oil from the groove travels through the hole and impinges onto the rocker arm body (cover) and further goes to the specified points, viz. valve tip and the push rod end, thus, ensuring the much accurate lubrication with improved utilization of the lubricant. Two-hole positioning is also an alternate for direct lubrication of contact points. In the present invention, rocker body (1) acts as deflector for oil to be reached at the contact/desired points. The jet from the bush bore impinges on the rocker arm body.
[0027] In addition to this unique lubrication method, the bushing of the present invention is located at the fulcrum point. The bushing is simply fitted into the fulcrum profile and the edges are crimped. Apart from welding and brazing, shrink fit and metallic adhesion modules are also implemented. Another aspect of the present invention is that the nut is fitted in the rocker arm body at the push rod end and it is attached to the rocker body without any additional joints, however, it is done by press-fitting, or crimping or caulking. Thus the extra operations of brazing or welding is avoided enhancing the cost efficiency and the operation time.
[0028] Technical advantages derived from the invention are as under:

- Considerable weight reduction (48% of the conventional means) has been achieved and thus there is decrease of inertia force.
- Added accuracy to lubrication and minimizes the wastage of lubrication oil.
- Elimination of additional manufacturing operations as no external passages are required.
- Cost and time of manufacturing is reduced.
- Enhancement in the cost efficiency and the operation time.
- Reduction in oil flow helped in reducing the emission, thereby leading to green initiative.
[0029] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be

practiced with modification within the spirit and scope of the embodiments as described herein.

We claim:
1 A rocker arm assembly comprising of rocker arm body (1), bushing (4), integrated profile (7) for contact point at valve end, contact pad (9), nut (3), and valve end tip (8); wherein,
- the rocker body (I) is having fulcrum profile (2) at its center level and it houses the bushing (4); wherein,
- the said busing (4) is having lubrication hole (5) and is fitted in the fulcrum profile (2) of the rocker arm body (1) by suitable means,
- Valve end tip (8) houses the contact pad (9) wherein the said contact pad (9) is an additional feature to valve end tip (8) for its smooth functioning.
2 A rocker arm assembly as claimed in claim 1, wherein the suitable means of fitting the bushing (4) in the fulcrum profile (2) are from riveting, screwing, metallic adhesion, threaded bush, structural cementing, caulking, etc., either taken individually or combination of thereof.

3 A rocker arm assembly as claimed in claim 1, wherein the lubrication means on the bushing are from two-hole lubrication, water packet with hole, annular grooves, either taken individually or combination thereof for better lubrication efficiency.
4 A rocker arm assembly as claimed in claim 1, wherein the rocker arm body is made from unitary sheet metal providing much more strength per unit of weight and is characterized by an integral lubrication passage (12); wherein the profile of the lubrication ^ passage is in such way that it provides added accuracy to lubrication and also minimizes the wastage of the lubricant.
5 A rocker arm assembly comprising of rocker arm body (1), bushing (4), integrated profile (7) for contact point at valve end, roller (10), nut (3), and valve end tip (8); wherein

- the rocker body (1) is having fulcrum profile (2) at its center level and it houses the bushing (4); wherein
- the said busing (4) is having lubrication hole (5) and is fitted in

the fulcrum profile (2) of the rocker arm body (1) by suitable means.