Internal-combustion engines – Poppet valve operating mechanism – Rocker
Reexamination Certificate
2001-03-12
2002-06-04
Denion, Thomas (Department: 3748)
Internal-combustion engines
Poppet valve operating mechanism
Rocker
C403S135000
Reexamination Certificate
active
06397805
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to internal combustion engines and more particularly to an improved retainer for a rocker arm coupling in an internal combustion engine.
2. Background of the Invention
In an overhead valve internal combustion engine, the valves of the engine are positioned over the cylinders containing the pistons of the engine. In many cases, the overhead valves are actuated by a rocker arm positioned over the overhead valves. A cam shaft positioned below the plurality of rocker arms actuates the plurality of rocker arms through a plurality of push rods.
A rocker arm coupling is interposed between each of the rockers arms and a valve stem of the plurality of overhead valves. The rocker arm coupling comprises a ball and socket coupling for translating the rocking motion of the rocker arm into reciprocating linear motion of the overhead valve.
Typically, the rocker arm coupling comprises a first and a second coupling member with a socket disposed in the first coupling member for receiving a ball extending from the second coupling member. The first coupling member is engaged with an end of the valve stem whereas the second coupling member is engageable with the rocker arm.
A retainer is interposed between the first and second coupling members for maintaining the ball of the second coupling member within the socket of the first coupling member. Typically, the retainer was a metallic spring clip which was receivable within a recess in the first coupling member and provided an interference fit with the ball extending from the second coupling member.
Although the metallic spring clip functioned properly for maintaining the ball within the socket of the rocker arm coupling, the metallic spring clip was difficult to insert into the recess in the first coupling member. Furthermore, the metallic spring clip complicated the insertion of the ball within the socket of the rocker arm coupling.
In my prior U.S. Pat. No. 6,199,526, I set forth a resilient retainer for a rocker arm coupling joining a valve assembly to a rocker arm assembly in an internal combustion engine. The rocker arm coupling comprises a first coupling member having a socket for receiving a ball extending from a second coupling member. The resilient retainer consists of unitary polymeric material comprising a resilient mounting portion and a resilient restricting portion. The resilient mounting portion is engageable with a recess delineated within the first coupling member for resiliently securing the resilient retainer. The resilient restricting portion permits insertion of the ball into the socket upon deformation of the resilient restricting portion with the resilient restricting portion inhibiting removal of the ball from the socket.
It is an object of this invention to provide an alternative to my prior U.S. Pat. No. 6,199,526 and to provide an improved retainer for a rocker arm coupling of internal combustion engine.
Another object of this invention is to provide an improved retainer for a rocker arm coupling in an internal combustion engine for inhibiting separation of a ball and a socket of the rocker arm coupling that is a substantial advancement in the prior art.
Another object of this invention is to provide an improved retainer for a rocker arm coupling in an internal combustion engine that facilitates the insertion of the ball within the socket of the rocker arm coupling.
Another object of this invention is to provide an improved retainer for a rocker arm coupling in an internal combustion engine that facilitates the insertion of the ball into the socket of the rocker arm coupling without the use of specialized tools required by the prior art.
Another object of this invention is to provide an improved retainer for a rocker arm coupling in an internal combustion engine that is made of a resilient polymeric material.
Another object of this invention is to provide an improved retainer for a rocker arm coupling in an internal combustion engine that is suitable for use with conventional rocker arm couplings of the prior art.
Another object of this invention is to provide an improved retainer for a rocker arm coupling in an internal combustion engine that is economical to manufacture and install.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed as being merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention with in the scope of the invention. Accordingly other objects in a full understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment of the invention.
SUMMARY OF THE INVENTION
A specific embodiment of the present invention is shown in the attached drawings. For the purpose of summarizing the invention, the invention relates to an improvement for an internal combustion engine having a valve assembly and a rocker arm assembly with a rocker arm coupling interposed therebetween. The rocker arm coupling comprises a first coupling member engageable relative to the valve assembly and a second coupling member engageable relative to the rocker arm assembly. The improvement comprises a retainer formed from a polymeric material for inhibiting separation of the first coupling member relative to the second coupling member.
In a more specific embodiment of the invention, the first coupling member has a socket for receiving a ball extending from the second coupling member and with an annular recess delineated within the first coupling member. The resilient retainer comprises a resilient mounting portion and a resilient restricting portion. The resilient mounting portion of the resilient retainer comprises a plurality of projections being engageable with the recess delineated within the first coupling member for resiliently securing the resilient retainer to the first coupling member. A plurality of voids are defined in the resilient mounting portion and located adjacent to said plurality of projections, respectively. The resilient restricting portion permits insertion of the ball into the socket defined in the first coupling member upon deformation of the resilient restricting portion. The resilient restricting portion inhibits removal of the ball from the socket. Preferably, the resilient retainer is a unitary polymeric material such as a unitary high temperature plastic material.
In one embodiment of the invention, the resilient mounting portion may comprise a projection extending from the resilient retainer. The projection is receivable within the recess delineated within the first coupling member upon deformation of the resilient retainer for resiliently securing the resilient retainer to the first coupling member.
In another embodiment of the invention, the resilient restricting portion comprises a resilient protuberance extending toward the socket. The resilient protuberance is tapered for permitting insertion of the ball into the socket upon deformation of the resilient protuberance and for inhibiting removal of the ball from the socket.
In still another embodiment of the invention, the resilient restricting portion comprises a resilient protuberance extending in an angular direction toward the socket for permitting insertion of the ball into the socket upon deformation of the resilient protuberance and for inhibiting removal of the ball from the socket.
The resilient restricting portion may comprise an annular resilient protuberance extending in an angular direction toward the socket for permitting insertion of the ball into the socket upon deformation of the resilient protuberance and for inhibiting removal of the ball from the socket. In the alternative, the resilient restricting portion comprises a plurality of resilient protuberances extending in a direction toward the socket for permitting insertion of the ball into the socket
Chang Ching
Denion Thomas
LandOfFree
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