Abstract: A valvetrain suitable for an internal combustion engine of a type that includes a combustion chamber, a moveable valve having a seat formed within the combustion chamber, and a camshaft. The valvetrain includes a rocker arm assembly having a rocker arm and an electrical device that either configures the rocker arm assembly or provides position feedback for a part of the rocker arm assembly. The valvetrain includes a framework that fits around a spark plug tube while holding a component of a circuit that includes the electrical device in a position adjacent the rocker arm assembly. The position may place the component in contact with or very close to the rocker arm assembly. This framework structure may effectively utilize the available space under a valve cover while facilitating correct positioning of the component in relation to the rocker arm assembly.

Abstract: An actuator control system suitable for providing single wire control of electromagnetic latch assemblies providing for cylinder deactivation or variable valve actuation in a valvetrain system. The system is adapted to control electromagnetic latch assemblies that require DC current in a first direction for latching and DC current in a reverse of the first direction for unlatching. The actuator control system includes an inverting DC/DC converter and switching elements. In some embodiments, the inverting DC/DC converter uses capacitors to store energy that drives the inverted current. In some embodiments, the inverting DC/DC converter serves a plurality of distinct groups of the electromagnets.

Abstract: A method of operating an internal combustion engine having an electrical circuit that includes a connection closed by abutment between two distinct parts, one of which is mounted to a rocker arm of a rocker arm assembly and another that is mounted to a part distinct from the rocker arm. The connection is structured such that the movement of the rocker arm causes relative motion between the surfaces of the distinct parts that close the connection. The relative motion causes the circuit resistance to transition between values within a first range and values within a second range. The transitions of resistance between those ranges are detected and their presence, absence, or timing used for purposes of providing diagnostic feedback or control.

Abstract: A valvetrain suitable for an internal combustion engine of a type that includes a combustion chamber, a moveable valve having a seat formed within the combustion chamber, and a camshaft. The valvetrain includes a rocker arm assembly having a rocker arm and an electrical device that either configures the rocker arm assembly or provides position feedback for a part of the rocker arm assembly. The valvetrain includes a framework that fits around a spark plug tube while holding a component of a circuit that includes the electrical device in a position adjacent the rocker arm assembly. The position may place the component in contact with or very close to the rocker arm assembly. This framework structure may effectively utilize the available space under a valve cover while facilitating correct positioning of the component in relation to the rocker arm assembly.

Abstract: An actuator control system suitable for providing single wire control of electromagnetic latch assemblies providing for cylinder deactivation or variable valve actuation in a valvetrain system. The system is adapted to control electromagnetic latch assemblies that require DC current in a first direction for latching and DC current in a reverse of the first direction for unlatching. The actuator control system includes an inverting DC/DC converter and switching elements. In some embodiments, the inverting DC/DC converter uses capacitors to store energy that drives the inverted current. In some embodiments, the inverting DC/DC converter serves a plurality of distinct groups of the electromagnets.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A method of operating an internal combustion engine having an electrical circuit that includes a connection closed by abutment between two distinct parts, one of which is mounted to a rocker arm of a rocker arm assembly and another that is mounted to a part distinct from the rocker arm. The connection is structured such that the movement of the rocker arm causes relative motion between the surfaces of the distinct parts that close the connection. The relative motion causes the circuit resistance to transition between values within a first range and values within a second range. The transitions of resistance between those ranges are detected and their presence, absence, or timing used for purposes of providing diagnostic feedback or control.

Abstract: A method of operating an electromagnetic latch assembly of a type that includes an electromagnet and a latch pin that is stable independently from the electromagnet in both first and second positions includes energizing the electromagnet systematically over a period in a manner that enhances the functionality of the electromagnetic latch assembly without causing the latch pin to move between the first and second positions. The period may be a period over which the electromagnetic latch assembly is too cold and the electromagnet may be energized in a manner that is effective for heating. Alternatively, the period may be one over which the electromagnetic latch assembly is subject to high inertial forces and the electromagnet may be energized in a manner that is effective to enhance latch pin retention.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A valvetrain includes a rocker arm assembly having a rocker arm and an electromagnetic latch assembly. A magnet of the latch assembly is housed within a chamber formed by the rocker arm. The chamber may be a retrofit hydraulic chamber. The magnet may be an electromagnet or a permanent magnet. A flux shifting bi-stable latch provides a sufficiently compact design. Isolation of the magnet within the rocker arm chamber may provide protection from metal particles carried by oil in an operating environment for the rocker arm assembly.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A method of operating an electromagnetic latch assembly of a type that includes an electromagnet and a latch pin that is stable independently from the electromagnet in both first and second positions includes energizing the electromagnet systematically over a period in a manner that enhances the functionality of the electromagnetic latch assembly without causing the latch pin to move between the first and second positions. The period may be a period over which the electromagnetic latch assembly is too cold and the electromagnet may be energized in a manner that is effective for heating. Alternatively, the period may be one over which the electromagnetic latch assembly is subject to high inertial forces and the electromagnet may be energized in a manner that is effective to enhance latch pin retention.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A valvetrain includes a rocker arm assembly having an electromagnetic latch housed in a chamber formed by a rocker arm. The chamber may be a retrofit hydraulic chamber. A flux shifting bi-stable latch provides a sufficiently compact design. Isolation of the magnetic elements within the rocker arm chamber may provide protection from metal particles carried by oil in an operating environment for the rocker arm assembly. Wiring connections to the rocker arms may be made through spring posts on the rocker arms. Connection to the rocker arms may be made with springs that can endure the rapid motion induced by the rocker arms. A wiring harness for the rocker arms may attach to hydraulic lash adjusters of the rocker arm assemblies. The rocker arm assemblies and their wiring may be formed into a unitary module that facilitates installation.

Abstract: A valvetrain includes a rocker arm assembly having a rocker arm and an electromagnetic latch assembly. A magnet of the latch assembly is housed within a chamber formed by the rocker arm. The chamber may be a retrofit hydraulic chamber. The magnet may be an electromagnet or a permanent magnet. A flux shifting bi-stable latch provides a sufficiently compact design. Isolation of the magnet within the rocker arm chamber may provide protection from metal particles carried by oil in an operating environment for the rocker arm assembly.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A valvetrain includes a rocker arm assembly having an electromagnetic latch housed in a chamber formed by a rocker arm. The chamber may be a retrofit hydraulic chamber. A flux shifting bi-stable latch provides a sufficiently compact design. Isolation of the magnetic elements within the rocker arm chamber may provide protection from metal particles carried by oil in an operating environment for the rocker arm assembly. Wiring connections to the rocker arms may be made through spring posts on the rocker arms. Connection to the rocker arms may be made with springs that can endure the rapid motion induced by the rocker arms. A wiring harness for the rocker arms may attach to hydraulic lash adjusters of the rocker arm assemblies. The rocker arm assemblies and their wiring may be formed into a unitary module that facilitates installation.