Patent ID: 9581228
Date: 2017-02-28
CPC Classifications: F16H,F16K

Claim:
1. An apparatus comprising: a cam having a cam surface to engage a valve stem; a first portion of the cam surface to engage the valve stem in a closed position; a second portion of the cam surface to engage the valve stem in an open position; a third portion of the cam surface adjacent the first portion and defining a curved profile, the third portion to engage the valve stem when the cam is rotated to a first intermediate position between the closed position and the open position; and a fourth portion of the cam surface between the second portion and the third portion and defining a linear profile, the fourth portion to engage the valve stem as the cam rotates between the first intermediate position and the open position, the fourth portion and the second portion form an angle of about 172 degrees to enable the curved profile of the third portion to have a radius of curvature that accelerates an angular rotation of the cam as the cam rotates to the closed position to overcome resistive forces.