Description ENGINE [001] Field of the Invention [002] This invention relates to an engine including an elephant foot assy and a method ■ developed for the assembly of this elephant foot assy. [003] Background of the Invention [004] In known diesel engine applications, the rotary motion of the camshaft is transferred to the rocker arm via a pushrod moving linearly back and forth. Various rocker arm designs are available. In one of these, the rocker arm rotates around its central axis back and forth and by the elephant foot assy this motion of the rocker arm is transferred to a bridge connecting the valves. [005] [006] The elephant foot assy incorporates a hollow shim pushing on this bridge and a stem whose lower end can move inside this shim and higher end is fastened to the rocker arm. Since the stem can move inside this shim, the motion of the rocker arm can smoothly be transferred to the bridge thereby preventing the valves from being damaged. [007] In known elephant foot assies in technique, the lower end of the stem is in a spherical shape having a greater diameter. The stem attains a cylindrical structure at the higher portions. There is a disc shaped flange at a certain part of the stem. The housing inside the shim is in a spherical form, wherein its opening faces upward towards the stem. The lower end of the stem is mounted in this housing. [008] After the stem is located to the shim, the opening of the shim is bent towards the stem by mechanical forming to prevent the disengaging of the stem from the shim. Because of the fact that the diameter of the lower end of the stem is greater, the stem can move inside the shim without detaching from it (Figure 1). In a known application of the technique as described in the United States Patent Document US5570665, an elephant foot assy of this kind is presented. However, before the mechanical forming, the shim is exposed to heat treatment in order to decrease the necessary force applied. This heat treatment causes formation of cracks at visible or invisible levels at the shim opening where the wall thickness is already small and thereby leading to the failure of the shim after being exposed to loading for a period of time. As a solution to this fact, heat treatment with local induction may be suggested, however since the elephant foot assy is already a small member (2-3 cm) this suggestion is not enough to eliminate the problem. [009] In another application, the opening of the shim is produced to have a ring shaped projection horizontally towards the inside direction. The size of the spherical part under the stem is such that it can pass through the circular cavity at the center of this projection. To prevent the shim from coming off back, a ring shaped O-ring is mounted between the flange and the shim, wherein its size is such that it can not pass through this cavity (Figure 2). However, significant problems like assembly difficulties and cost increases arise from the usage of the O-ring. Moreover, in time, a cavity is formed between the stem and the shim as a result of the deformation of the O-ring. This cavity causes an increase in fuel consumption, engine noise and the emission amounts by changing the opening and closing frequency of the valves. [010] Although the elephant foot assy is a small member, it has an important function because it provides the connection between the rocker arm and the valves opening to the barrels. In a situation wherein this member fails or the stem detaches from the shim somehow, the valves fall into the barrel where the piston moves with a considerable speed and thus irreparable damages in the engine take place. [011] Brief Description of the Invention [012] The aim of the present invention is the realization of an engine incorporating an elephant foot assy mounted without a heat treatment or mechanical forming, thus is more reliable and has a longer life-span. [013] Another aim of the present invention is the realization of an engine incorporating a low cost elephant foot assy that is mounted easily. [014] The elephant foot assy used in the engine designed to fulfill the objectives of the present invention, incorporates a shim comprising a housing with an opening with a certain diameter (φl) and a stem attached to this shim wherein it can move at one end. At the inside surface of the shim, there is a projection forming a throat with a smaller diameter (φ2) than the diameter of shim opening. The maximum diameter of the spherical lower end of the stem (φ3) is a bit larger than the diameter of this throat (φ3 > φl). When the stem is forced into the shim, the widest section of the spherical portion of the stem passes through the throat by contracting as a result of elastic de¬ formation and after it passes through, it expands approximately to its original dimensions. Therefore, the stem does not detach from the shim. [015] By means of the elephant foot assy of the engine and the assembly method in accordance with the present invention, there is no need to employ any other additional parts and/or to apply a heat treatment procedure. By these features, the problems of the prior art is solved at a low cost. [016] Detailed Description of the Invention [017] The engine designed to fulfill the above mentioned objectives of the present invention is illustrated on the attached figures where: [018] Fig. 1 - is a cross-sectional view of an elephant foot assy according to the prior art. [019] Fig. 2 - is a cross-sectional view of another elephant foot assy and its assembly stages in accordance with the prior art. [020] Fig. 3 - is a detailed representation of a part of the engine according to the present invention. [021] Fig. 4 - is a cross-sectional view of the elephant foot assy on the engine designed according to the present invention. [022] Fig. 5 - is a cross-sectional view of the elephant foot assy used in the engine of the present invention, before the assembly. [023] Fig. 6 - is a detailed cross-sectional view of the elephant foot assy used in the engine of the present invention, during the assembly. [024] Fig. 7 - is a cross-sectional view of the elephant foot assy used in the engine of the present invention, after the assembly. [025] Elements shown on figures are numbered as follows: 1. Engine 2. Camshaft 3. Tappet 4. Pushrod 5. Rocker arm 6. Bridge 7. Valve [026] 11. Elephant foot assy [027] 12. Stem [028] 13. Shim [029] 14. Opening [030] 15. Housing [031] 16. Projection [032] 17. Throat [033] The engine (1) of the present invention comprises a camshaft (2) rotating about an axis, a pushrod (4) wherein this rotary motion is transferred as linear motion via a tappet (3), a rocker arm (5) actuated by this pushrod and valves (7) connected to this rocker arm by an elephant foot assy (11). The valves provide the intake of clean air to the barrel (not shown in figures) and the exhaust of polluted air. During the cycle of the engine, the piston (not shown in figures) moves inside the barrel linearly back and forth and this linear motion is transferred to the crankshaft (not shown in figures) as rotary motion. [034] The elephant foot assy (11) comprises a shim (13) pushing to the valves (7) or the bridge (6) connecting them and a stem (12) one end of which is attached to this shim and the other end pushes to the rocker arm (5). [035] The shim (13) comprises a housing (15) that opens out with an opening (14) having a diameter of φl. This housing (15) is preferably hemispherical. A throat (17) with a diameter of q>2 is formed by a ring shaped projection (16) at the entrance of the housing (15). The diameter of throat (17) is smaller than the diameter of the opening (14) (φl > φ2). In order to increase the structural strength, the cross-section of this projection is produced in a right triangle shape having one of its orthogonal sides in contact with the internal wall of the housing and a rounded corner facing the inside of the housing. In one application of the present invention, the bottom side is curved at a certain degree. [036] The stem (12) comprises a cylindrical portion with a diameter φ4 and, at the end of this, a spherical portion with a maximum diameter of φ3. The diameter of the spherical portion is larger than the diameter of the cylindrical portion (φ3 > φ4). Furthermore, the diameter of the cylindrical portion is smaller than the diameter of the throat (φ2 > φ4) and the diameter of the spherical portion is larger than the diameter of the throat (φ3 > φ2). When the stem (12) is forced into the shim (13), it passes through the throat (17) by contracting as a result of elastic deformation at the section of contact and after passing through, it expands approximately to its original dimensions. Therefore, the stem (12) does not come off from the shim (13). [037] Industrial Applications of the Present Invention [038] A force of 40 - 80 N applied to the stem from the top while keeping the shim stationary, is enough for the assembly of the parts of the elephant foot assy in the engine according to the present invention. Under normal operating conditions, the stem and the shim mounted by this method do not disengage. [039] In line with this principle, while it is possible to develop several applications of the mechanism in accordance with the present invention, the invention actually is as described in the Claims and can not be limited to the samples explained here.