Patent ID: 7938632
Filing Date: 2011-05-10
Classification: F04B,Y10T

Abstract:
1. A pump, comprising: a constant velocity cam driven by a rotary shaft; first and second cylinders; first and second pistons reciprocable rectilinearly in the respective first and second cylinders; first and second cam followers which, together with the constant velocity cam, couple the rotary output shaft to said first and second pistons, respectively, for converting rotary motion of the constant velocity cam into reciprocatory motion of said first and second pistons 180° out of phase with one another; at least one guide rail extending parallel to an axis along which the pistons are rectilinearly reciprocable; first and second cam follower sliders each of which is slidably mounted on said at least one guide rail and each of which carries thereon the respective first or second cam follower; and at least one spring acting on at least one of the first and second cam follower sliders and simultaneously urging both said cam followers toward each other to engage the cam surface of said constant velocity cam; wherein an entirety of the at least one spring is moveable relative to the first and second cylinders.