Abstract: A press mounted cam has a slide guided on an adapter by structural features including as one or more T blocks fixed to the slide and received in a respective channel formed in the adapter. In an aerial cam embodiment, a vertical clearance space is provided between the T block and adapter channel such that positive driving engagement between cam surfaces on the slide and the adapter is momentarily delayed after the initial engagement of the slide and driver surfaces to let the momentum of the slide be absorbed prior to the beginning of positive driving by the press motion, reducing shock and noise. The slide is laterally located with respect to the driver by an upwardly projecting locator-guide key on the driver received in a central channel in the slide. A positive return is provided by engagement of a driver key having T features received in a T-shaped slide channel and captured therein when the slide is driven laterally.