RETENTION DEVICE FOR VALVE ACTUATING MECHANISM

Abstract

A retention device to secure a finger follower and lash adjuster of a valve actuating mechanism together includes a ring member disposed in a groove of a movable piston of the lash adjuster. The retention device also includes a plurality of connecting members formed from the finger follower and extending axially below the ring member and about a portion of the lash adjuster to engage the ring member in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to valve actuating mechanisms for engines and, more particularly, to a retention device for a valve actuating mechanism for an engine.

2. Description of the Related Art

It is known to provide valve actuating mechanisms to open and close valves of an engine such as an internal combustion engine. These valve actuating mechanisms may be of a finger follower type including a finger follower having a pallet or web engaging a stem of the valve and a dome socket engaging a rounded end of a hydraulic lash adjuster supported by a cylinder head of the engine. The dome socket is known to have a dome with a concave recess or socket therein. Typically, a circular opening or orifice is provided in the dome for spraying lubrication fluid from the dome socket into a camshaft compartment for lubricating a cam and cam follower and associated components of the valve actuating mechanism.

It is also known to provide a device for securing the finger follower and hydraulic lash adjuster together. For example, U.S. Pat. No. 5,775,280 to Schmidt et al. discloses a securing device for an actuating lever in a valve control mechanism of an internal combustion engine. In this patent, a hydraulic lash adjuster is disposed below a spherical end of a finger follower or lever and has an undercut for receiving a connecting element in the form of a sheet metal retention clip so that the finger follower and the hydraulic lash adjuster form a structural unit. The sheet metal retention clip has a thickness which is smaller than the width of the undercut, so that the connecting element does not spring open during pivoting movements of the finger follower, but bears firmly against the socket-like portion of the finger follower and thus does not cause an additional increase of friction in the valve actuating mechanism. The sheet metal retention clip exhibits a generally U-shaped configuration and is comprised of an arm, which engages a top surface of the finger follower, and a second, bifurcated arm which is received in the undercut. An intermediate portion connects the arms to each other, with the arms additionally formed with retaining lugs for securing the clip in place.

The above-described patented sheet metal retention clip suffers from the disadvantage that this clip always effects a relative movement in relation to the finger follower or the lash adjuster. Another disadvantage is that the constant relative movement occurring between the retention clip and the finger follower and between the retention clip and the lash adjuster subjects the valve actuating mechanism to additional friction, which is undesired. A further disadvantage of the retention clip is that it does not bear firmly against the finger follower in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower.

In addition, U.S. Pat. No. 4,676,203, which is the U.S. equivalent of German Patent No. DE 3500524 C2, to Nouno discloses a rocker arm spring for a valve actuating mechanism of an internal combustion engine. The rocker arm spring has an upper arm engaging a rocker arm and a lower arm engaging a socket of a universal pivot. The rocker arm spring holds a shaft of the universal pivot and the socket together and serves to bias the free end of the rocker arm in contact with the stem of the intake or exhaust valve. The upper arm of the spring has side edges bent down at a right angle to increase the flexural rigidity of the upper arm.

The above-described patented rocker arm spring suffers from the disadvantage that the constant relative movement occurring between the spring and the finger follower and between the spring and the lash adjuster subjects the valve actuating mechanism to additional friction, which is undesired. Another disadvantage of the rocker arm spring is that it does not bear firmly against the finger follower in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower.

Therefore, it is desirable to provide a retention device to secure the actuating lever or finger follower and the support member or lash adjuster of a valve actuating mechanism to one another, without increasing a friction in the valve actuating mechanism. It is also desirable to provide a retention device to bear firmly against the finger follower in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower. Thus, there is a need in the art to provide a retention device for a valve actuating mechanism that meets at least one of these desires.

SUMMARY OF THE INVENTION

It is, therefore, one object of the present invention to provide a retention device to secure the finger follower and the lash adjuster of a valve actuating mechanism to one another.

It is another object of the present invention to provide a retention device to secure the finger follower and the lash adjuster of a valve actuating mechanism to one another, without increasing a friction in the valve actuating mechanism.

To achieve one or more of the foregoing objects, the present invention is a retention device to secure a finger follower and lash adjuster of a valve actuating mechanism together. The retention device includes a ring member disposed in a groove of a movable piston of the lash adjuster. The retention device also includes a plurality of connecting members adapted to be formed from the finger follower and extending axially below the ring member and about a portion of the lash adjuster to engage the ring member in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower.

One advantage of the present invention is that a new retention device is provided for a valve actuating mechanism. Another advantage of the present invention is that the retention device has a plurality of connecting members as in-die formed tabs that may engage a ring member or a groove of a moveable piston of a supporting component such as a lash adjuster. Yet another advantage of the present invention is that the connecting members engage the ring member or groove in all pivoted positions of an actuating lever such as a finger follower. A further advantage of the present invention is that the retention device ensures that the connecting members abut firmly on the finger follower in all operating positions of the valve actuating mechanism and, due to the tilting movement of the finger follower, can move freely from its upper to its lower and from its lower to its upper edge in the undercut of the moveable piston of the lash adjuster. Yet a further advantage of the present invention is that the retention device is utilized to realize a structural unit of the actuating lever and the support member so that assembly problems for customers are avoided. Still another advantage of the present invention is that the retention device prevents the erroneous installation of the actuating lever in the valve drive, e.g. a position turned by 180 degrees, so that the socket-type cavity of the finger lever is placed correctly on the support member and not on the valve stem end by mistake. A still further advantage of the present invention is that the retention device has connecting members formed into the finger lever spherical recess area of the roller finger follower, by forming in the stamping process. Yet a still further advantage of the present invention is that the retention device has connecting elements formed into the finger lever spherical recess area, thereby eliminating the need for a secondary operation and added components.

Other objects, features, and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary view a valve actuating mechanism having a retention device, according to the present invention, illustrated in operational relationship with a portion of an engine.

FIG. 2 is a top perspective view of the retention device, according to the present invention, of the valve actuating mechanism of FIG. 1.

FIG. 3 is a bottom perspective view of the retention device, according to the present invention, of the valve actuating mechanism of FIG. 1.

FIG. 4 is an enlarged view of a portion of the retention device, according to the present invention, of the valve actuating mechanism of FIG. 3.

FIG. 5 is a fragmentary side elevational view of the retention device, according to the present invention, of the valve actuation mechanism of FIG. 1.

FIG. 6 is a fragmentary side elevational view of another embodiment, according to the present invention, of the retention device for the valve actuating mechanism of FIG. 1.

FIG. 7 is a fragmentary side elevational view of yet another embodiment, according to the present invention, of the retention device for the valve actuating mechanism of FIG. 1.

FIG. 8 is a fragmentary side elevational view of still another embodiment, according to the present invention, of the retention device for the valve actuating mechanism of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to the drawings, and in particular FIG. 1, one embodiment of a retention device 10, according to the present invention, for a valve actuating mechanism, generally indicated at 12, of a finger follower type is shown for an engine, generally indicated at 14. The engine 14 is of an overhead cam type having a cylinder head 16 including an inlet or exhaust port 18. The engine 14 also includes a valve 20 having a head 22 and a stem 24 extending from the head 22. The engine 14 includes a spring 26 disposed about the stem 24 that biases the head 22 of the valve 20 to a closed position. It should be appreciated that the engine 14 is conventional and known in the art.

Referring to FIGS. 1 through 5, the valve actuating mechanism 12 includes an actuating lever or finger follower, generally indicated at 28, having a lever body 29 with a base wall 30 and a pair of opposed side walls 32 extending substantially parallel from the base wall 30 and an aperture 33 extending through each of the side walls 32. The finger follower 28 also includes a pallet or actuating pad 34 at one end of the lever body 29 engaging the stem 24 of the valve 20. The finger follower 28 further includes a roller or cam follower 36 disposed between the side walls 32 and having an outer surface 38 engaged by an associated cam 40 of a camshaft 42 of the valve actuating mechanism 12. The roller 36 is generally circular in shape and is rotatably mounted to the side walls 32 by a pin 44 extending through the roller 36 and the apertures 33 in the side walls 32 of the lever body 29. It should be appreciated that the roller 36 has one or more bearing members 45 disposed about the pin 44 to allow the roller 36 to rotate relative to the pin 44.

The finger follower 28 also includes a dome socket 46 disposed between the side walls 32 at an end of the lever body 29 opposite the actuating pad 34. The finger follower 28 further includes a tab 47 extending outwardly from the end of the lever body 29 adjacent the dome socket 46. The finger follower 28 is made of a metal material and is integral, unitary, and one-piece. It should be appreciated that the dome socket 46 also includes a lubrication spray orifice (not shown) extending therethrough.

The valve actuating mechanism 10 further includes a support member or hydraulic lash adjuster 48 that is supported by the cylinder head 16. The hydraulic lash adjuster 48 has a movable piston with a rounded end 50 disposed in and engaging the dome socket 46 of the finger follower 28. The rounded end 50 may include a groove 51 extending inwardly radially and circumferentially. It should be appreciated that the dome socket 46 receives lubrication fluid via the lash adjuster 48 and the lubrication fluid is sprayed through the lubrication spray orifice toward the outer surface of the associated roller 36 for lubricating the roller 36 and the associated cam 40, and, by the resulting spray, lubricating the pallet 34 which actuates the valve 20.

Referring to FIGS. 3 through 5, one embodiment of the retention device 10, according to the present invention, is shown. The retention device 10 holds the actuating lever such as the finger follower 28 and the support member such as the lash adjuster 48 together. The retention device 10 includes a ring member 52 disposed in the groove 51 of the rounded end 50 of the moveable piston of the lash adjuster 48. The ring member 52 is generally circular in shape and of a snap ring type. The ring member 52 is made of a metal material. The ring member 52 is disposed in the groove 51 of the movable piston and extends radially outwardly past the exterior surface of the movable piston. It should be appreciated that the ring member 52 could be formed as part of the rounded end 50 of the moveable piston as opposed to being a separate member. It should also be appreciated that the ring member 52 is optional.

The retention device 10 also includes one or more connecting members 54 formed from the finger follower 28 and cooperating with the ring member 52. In this embodiment, the connecting members 54 are generally rectangular shaped and extend axially. As illustrated, two opposed connecting members 54 are disposed about and cooperate with the ring member 52. The connecting members 54 are in-die formed from the dome socket 46 and cantilevered to extend downwardly and axially. Once formed, an aperture 56 extends between each connecting member 54 and the dome socket 46. The connecting members 54 form a groove 58 to receive the ring member 52. The connecting members 54 are angled inwardly to extend radially below and past the ring member 52. The connecting members 54 are made of a metal material. The connecting members 54 and dome socket 46 are integral, unitary, and one-piece. It should be appreciated that the connecting members 54 are formed to be angled inward to aid the retention of the connecting members 54 to the ring member 52 disposed in the groove 51 of the movable piston of the lash adjuster 48. It should also be appreciated that the connecting members 54 engage the ring member 52 in all pivoted positions of the finger follower 28. It should further be appreciated that a die (not shown) is used to form the connecting members 54 in the dome socket 46 in a stamping process.

In operation of the valve actuating mechanism 12, the camshaft 42 of the engine 14 rotates and the cam 40 of the camshaft 42 actuates the finger follower 28. The lash adjuster 48 acts as a pivot about which the finger follower 28 is actuated to open and close an associated valve 20 of the engine 14. Lubrication fluid from the lash adjuster 48 is provided to the dome socket 46 through the opening or orifice in the rounded end 50 of the lash adjuster 48. The lubrication fluid in the dome socket 46 is sprayed through the orifice into the camshaft compartment for lubricating the cam 40 and roller 36 and associated components of the valve actuating mechanism 12. It should be appreciated that the connecting members 54 bear firmly against the ring member 52 in all operating positions of the valve actuating mechanism 12.

Referring to FIG. 6, another embodiment, according to the present invention, of the retention device 10 is shown for the valve actuating mechanism 12. Like parts of the retention device 10 have like reference numerals increased by one hundred (100). The retention device 110 holds the finger follower 28 and the lash adjuster 48 together. In this embodiment, the retention device 110 includes a ring member 152 disposed in the groove 51 of the rounded end 50 of the moveable piston of the lash adjuster 48. The ring member 152 is generally circular in shape and of a snap ring type. The ring member 152 is made of a metal material. It should be appreciated that the ring member 152 could be formed as part of the rounded end 50 of the moveable piston as opposed to being a separate member.

The retention device 110 also includes one or more connecting members 154 formed on the finger follower 28 and cooperating with the ring member 152. In this embodiment, the connecting members 154 are generally rectangular shaped and extend axially. As illustrated, two opposed connecting members 154 are disposed about and cooperate with the ring member 152. The connecting members 154 are in-die formed from the dome socket 46. The connecting members 154 form a groove 158 to receive the ring member 152. Each of the connecting members 154 includes a tab 160 extending radially from an interior surface. In this embodiment, the tab 160 is generally triangular shaped and extend radially inwardly below and past the ring member 152. It should be appreciated that the tabs 160 are formed to aid the retention of the connecting members 154 to the ring member 152 disposed in the groove 51 of the movable piston of the lash adjuster 48. The operation of the retention device 110 is similar to the retention device 10.

Referring to FIG. 7, yet another embodiment, according to the present invention, of the retention device 10 is shown for the valve actuating mechanism 12. Like parts of the retention device 10 have like reference numerals increased by two hundred (200). The retention device 210 holds the finger follower 28 and the lash adjuster 48 together. In this embodiment, the retention device 210 includes a ring member 252 disposed in the groove 51 of the rounded end 50 of the moveable piston of the lash adjuster 48. The ring member 252 is generally circular in shape and of a snap ring type. The ring member 252 is made of a metal material. It should be appreciated that the ring member 252 could be formed as part of the rounded end 50 of the moveable piston as opposed to being a separate member.

The retention device 210 also includes one or more connecting members 254 formed on the finger follower 28 and cooperating with the ring member 252. In this embodiment, the connecting members 254 are generally rectangular shaped and extending axially. As illustrated, two opposed connecting members 254 are disposed about and cooperate with the ring member 252. The connecting members 254 are in-die formed from the dome socket 46. The connecting members 254 form a groove 258 to receive the ring member 252. Each of the connecting members 254 includes a tab 260 extending radially from an interior surface. In this embodiment, the tab 260 is generally “L” shaped and extends radially inwardly below and past the ring member 252. It should be appreciated that the tabs 260 are formed to aid the retention of the connecting members 254 to the ring member 252 disposed in the groove 51 of the movable piston of the lash adjuster 48. The operation of the retention device 210 is similar to the retention device 10.

Referring to FIG. 8, still another embodiment, according to the present invention, of the retention device 10 is shown for the valve actuating mechanism 12. Like parts of the retention device 10 have like reference numerals increased by three hundred (300). The retention device 310 holds the finger follower 28 and the lash adjuster 48 together. In this embodiment, the retention device 310 includes one or more connecting members 354 formed on the finger follower 28 and cooperating with an axially extending groove 51 of the rounded end 50 of the lash adjuster 48. In this embodiment, the connecting members 354 are generally rectangular shaped and extending axially. As illustrated, two opposed connecting members 354 are disposed about and cooperate with the axially extending groove 51 of the rounded end 50. The connecting members 354 are in-die formed from the dome socket 46 of the finger follower 28. Each of the connecting members 354 includes a tab 360 extending radially from an interior surface. In this embodiment, the tab 360 is generally rectangular shaped and extends radially inwardly into the axially extending groove 51. It should be appreciated that the tabs 360 are formed to aid the retention of the connecting members 354 to the groove 51 of the movable piston of the lash adjuster 48. The operation of the retention device 310 is similar to the retention device 10.

The retention device 10, 110, 210, 310 of the present invention has one or more connecting members 54, 154, 254, 354 either cooperating with a ring member 52, 152, 252 placed in a groove 51 of a moveable piston of a supporting component such as a lash adjuster 48 or cooperating with the groove 51 of a moveable piston of a supporting component such as a lash adjuster 48. The connecting members 54, 154, 254, 354 of the present invention extend axially with enough distance to ensure that the connecting members 54, 154, 254, 354 of the present invention abut firmly on the lever body 29 of the finger follower 28 in all operating positions of the valve actuating mechanism 12. The retention devices 10, 110, 210, 310 of the present invention prevent an erroneous installation of the finger follower 28, e.g. a position turned by 180 degrees, so that the dome socket 46 is placed correctly on the rounded end 50 of the lash adjuster 48. The retention devices 10, 110, 210, 310 of the present invention have the connecting members 54, 154, 254, 354 formed into the dome socket 46, eliminating the need for a secondary operation and added components.

The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.

Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.

Claims

1. A retention device to secure a finger follower and lash adjuster of a valve actuating mechanism together comprising: a ring member adapted to be disposed in a groove of a moveable piston of the lash adjuster; anda plurality of connecting members adapted to be formed from the finger follower and extending axially below said ring member and about a portion of the lash adjuster to engage said ring member in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower.

2. A retention device as set forth in claim 1 wherein said connecting members are cantilevered to extend toward said ring member.

3. A retention device as set forth in claim 1 wherein said connecting members form a groove to receive said ring member.

4. A retention device as set forth in claim 1 wherein said connecting members are angled inwardly to extend radially below and past said ring member.

5. A retention device as set forth in claim 1 wherein said connecting members include a tab extending radially from an interior surface thereof and below and past said ring member.

6. A retention device to secure a finger follower and lash adjuster of a valve actuating mechanism together comprising: a plurality of connecting members adapted to be formed from the finger follower and extending axially about a portion of the lash adjuster and adapted to engage a groove of the lash adjuster in all operating positions of the valve actuating mechanism as a result of the pivoting motion of the finger follower.

7. A retention device as set forth in claim 6 wherein said connecting members are spaced from each other about the groove.

8. A retention device as set forth in claim 6 wherein each of said connecting members includes a tab extending radially from an interior surface thereof.

9. A retention device as set forth in claim 8 wherein said tab is generally rectangular shaped and adapted to extend radially inwardly into the groove.

10. A retention device as set forth in claim 6 wherein said connecting members are generally rectangular shaped.

11. A valve actuating mechanism for an engine comprising: a finger follower having one end adapted to engage a valve of the engine;a lash adjuster adapted to be supported by the engine, said lash adjuster having a movable piston with a rounded end and a groove in said rounded end; anda retention device to secure said finger follower and said lash adjuster together and comprising a ring member disposed in said groove of said moveable piston and a plurality of connecting members formed from said finger follower and extending axially below said ring member and about said rounded end of said lash adjuster to engage said ring member in all operating positions of said valve actuating mechanism as a result of the pivoting motion of said finger follower.

12. A valve actuating mechanism as set forth in claim 11 wherein said connecting members are cantilevered to extend toward said ring member.

13. A valve actuating mechanism as set forth in claim 11 wherein said connecting members form a groove to receive said ring member.

14. A valve actuating mechanism as set forth in claim 11 wherein said connecting members are angled inwardly to extend radially below and past said ring member.

15. A valve actuating mechanism as set forth in claim 11 wherein said connecting members include a tab extending radially from an interior surface thereof and below and past said ring member.

16. A valve actuating mechanism for an engine comprising: a finger follower having one end adapted to engage a valve of the engine;a lash adjuster adapted to be supported by the engine, said lash adjuster having a movable piston with a rounded end and a groove in said rounded end; anda retention device to secure said finger follower and said lash adjuster together and comprising a plurality of connecting members formed from said finger follower and extending axially about said rounded end of said lash adjuster to engage said groove in all operating positions of said valve actuating mechanism as a result of the pivoting motion of said finger follower.

17. A valve actuating mechanism as set forth in claim 16 wherein said connecting members are spaced from each other about said groove.

18. A valve actuating mechanism as set forth in claim 16 wherein each of said connecting members includes a tab extending radially from an interior surface.

19. A valve actuating mechanism as set forth in claim 18 wherein said tab is generally rectangular shaped and extends radially inwardly into said groove.

20. A valve actuating mechanism as set forth in claim 16 wherein said wherein said connecting members are generally rectangular shaped and extending axially.