US Patent 7882814 Inner arm stop for a switchable rocker arm

A roller finger follower assembly for variably activating a valve in an internal combustion engine includes at least one vertical recessed channel formed inside an outer arm and a shaft. The channel includes a machined upper surface closing the channel. The shaft engages with the recessed channel, the shaft reciprocates within the recessed channel, and the upper surface stops an upward movement of the shaft.