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A cam and cam follower apparatus translates linear cam bar movement to perpendicular valve stem actuation in an injection molding system. The cam bars reciprocate up and down on linear bearing rails such that an actuation plate, fitted with a plurality of valve stems, is cycled normal to the directi

A cam and cam follower apparatus translates linear cam bar movement to perpendicular valve stem actuation in an injection molding system. The cam bars reciprocate up and down on linear bearing rails such that an actuation plate, fitted with a plurality of valve stems, is cycled normal to the direction of the cam bar movement via cam followers traveling within cam slots in the cam bars. The cam slots in the cam bars are profiled such that the cam followers affect the speed and force at which the valve stems travel while at the same time reducing frictional effects and their associated power requirement. The cam followers of the valve stem actuation plate travel in cam slots in the cam bars from a valve stem forward position, to a valve stem retracted position and ultimately, the entire actuation plate may be removed from the cam bars for maintenance via open ended slots in the cam bars.

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1. A cam apparatus for a valve stem actuator, the cam apparatus comprising: a plurality of cam bars, movably mounted on a plurality of bearing rails, the plurality of cam bars having a plurality of profiled cam slots;a plurality of cam followers joined to an actuation plate of a hot runner having a

1. A cam apparatus for a valve stem actuator, the cam apparatus comprising: a plurality of cam bars, movably mounted on a plurality of bearing rails, the plurality of cam bars having a plurality of profiled cam slots;a plurality of cam followers joined to an actuation plate of a hot runner having a plurality of valve stems mounted on the actuation plate, the plurality of valve stems are simultaneously translated through a gate open position, a gate closed positioned, and a service position, via travel of the plurality of cam followers, attached to the actuation plate, in the plurality of profiled cam slots; anda locking pin for removal of the actuation plate and the plurality of valve stems for servicing, the locking pin inserted through a frame assembly of the hot runner and into the plurality of cam bars, the locking pin to ensure position of the plurality of valve stems is maintained upon re-installation of the actuation plate, to ensure accuracy of alignment of each valve stem to a respective gate orifice,whereby the plurality of cam followers and the actuation plate configured to be removed through a plurality of exit slots from the plurality of cam bars which have openings on their clamp face, so that the actuation plate and the plurality of valve stems is free of the hot runner for ease of maintenance. 2. The cam apparatus according to claim 1, wherein: the plurality of profiled cam slots have a profile wherein linear movement of the profile of the plurality of profiled cam slots causes the plurality of cam followers to translate the actuation plate to a plurality of perpendicular positions. 3. The cam apparatus according to claim 2, wherein: the profile of the plurality of profiled cam slots has a first position, wherein when in the first position, the plurality of cam followers of the actuation plate move the plurality of valve stems to a gate closed position. 4. The cam apparatus according to claim 3, wherein: the profile of the plurality of profiled cam slots has a second position, wherein when in the second position, the plurality of cam followers of the actuation plate move the plurality of valve stems to the gate open position. 5. The cam apparatus according to claim 4, further comprising: a plurality of mechanical stops, attached to any one of a backing plate and the actuation plate, for limiting movement of the plurality of cam followers in the plurality of profiled cam slots to the second position. 6. The cam apparatus according to claim 1, wherein: a profile of the plurality of profiled cam slots has a third position, wherein when in the third position, the plurality of cam followers disengage from a second position of the profile and align in the plurality of exit slots in the plurality of cam bars and move the actuation plate to the service position. 7. The cam apparatus according to claim 1, further comprising: a plurality of mechanical stops, attached to either the actuation plate or a backing plate, for limiting movement of the plurality of cam followers in the plurality of profiled cam slots a first position and a third position. 8. The cam apparatus according to claim 1, wherein: the plurality of exit slots terminate in a plurality of openings on a plurality of clamp faces on the plurality of cam bars through which the plurality of cam followers may fully disengage the actuation plate from the plurality of cam bars. 9. The cam apparatus according to claim 1, wherein: the plurality of cam bars are moved to a third position such that the plurality of cam followers are aligned in the plurality of exit slots within the plurality of cam bars. 10. The cam apparatus according to claim 9, wherein: the locking pin is engaged through the frame assembly and into the plurality of cam bars. 11. The cam apparatus according to claim 10, wherein: the actuation plate is removed by sliding the plurality of cam followers along the plurality of exit slots in the plurality of cam bars. 12. The cam apparatus according to claim 11, wherein: the actuation plate is disengaged from the plurality of cam bars via a plurality of openings on clamp faces on the plurality of cam bars through which the plurality of cam followers may exit the plurality of cam bars. 13. The cam apparatus according to claim 12, wherein: movement of the plurality of cam followers is limited in the plurality of profiled cam slots to the third position via a plurality of mechanical stops, attached to either the actuation plate or a backing plate. 14. The cam apparatus according to claim 1, wherein: a profile of the plurality of profiled cam slots has a first position at which the plurality of cam followers, attached to the actuation plate, cause the plurality of valve stems to be in a gate closed position. 15. The cam apparatus according to claim 1, wherein: a profile of the plurality of profiled cam slots has a second position at which the plurality of cam followers, attached to the actuation plate, cause the plurality of valve stems to be in the gate open position. 16. The cam apparatus according to claim 1, wherein: a profile of the plurality of profiled cam slots has a third position at which the plurality of cam followers, attached to the actuation plate, are disengaged from a second position and poised in an exit slot for imminent removal. 17. The cam apparatus according to claim 1, wherein: a plurality of mechanical stops are attached to any one of the actuation plate and to a backing plate, to limit an amount of travel by the actuation plate in certain phases of travel to ensure precise location is achieved and to prevent excessive injection force from being transferred to the plurality of cam followers. 18. A hot runner having the cam apparatus of any preceding claim. 19. A molding system including a hot runner having the cam apparatus of any preceding claim.