Development of a switching roller finger follower for cylinder deactivation in internal combustion engines

A system for preloading a latch used in controlling variable valve actuation in an internal combustion engine having a first and second cam each comprising a base circle portion and a lift portion, the system comprising:

• a rocker arm assembly for operative engagement with the cams;
• the rocker arm assembly comprising:
• a first arm for operatively engaging the first cam for a first desired lift profile, a second arm for operatively engaging the second cam for a second desired lift profile, the second arm comprising a selectively -activatable latch to operatively engage the second arm with the first arm;
• the selectively-activatable latch responsive to at least one of supplied oil pressure and released oil pressure;
• and
• wherein the selectively-activatable latch is structured to switch between one of the first desired lift profile and the second desired lift profile to the other of the first desired lift profile and the second desired lift profile, wherein the switching comprises the selectively-activatable latch being coupled to at least one of supplied oil pressure and released oil pressure prior to the first and second arms being engaged with the base circle portion of each of the respective first and second cams.

A system for preloading a latch used in controlling variable valve actuation in an internal combustion engine, the system comprising:

• at least a first and second cam each comprising a base circle portion and a lift portion;
• a rocker arm assembly for operative engagement with the cams,
• the rocker arm assembly comprising:
• a first arm for operatively engaging the first cam for a first desired lift profile, a second arm for operatively engaging the second cam for a second desired lift profile, the second arm comprising a selectively-activatable latch to operatively engage the second arm with the first arm;
• and
• an oil control valve structured to receive a switching communication that commands switching between one of the first desired lift profile and the second desired lift profile to the other of the first desired lift profile and the second desired lift profile, the oil control valve operatively coupled to the rocker arm assembly and responsive to the switching command to at least one of supply and release oil pressure to operate the latch prior to the first and second arms being engaged with the base circle portion of each respective first and second cams.