Electric pump

Claim 1

An injection pump having an input shaft capable of being rotated by an outside source of power, said pump comprising: housing member rotatably receiving said input shaft, said shaft having a cam eccentrically mounted thereon, said housing positioning ball bearing assembly means on opposite sides of said cam, for rotatably supporting said shaft, said cam carrying a further ball bearing assembly means around its periphery, said housing also including pumphead receiving means extending through a wall of said housing; pumphead means in communication with said further ball bearing assembly means, said pumphead means including; mounting means adapted to be received by said pumphead receiving means, said mounting means being axially bored and carrying means within said bore for (1) reciprocatingly receiving a plunger and (2) receiving spring means for biasing said plunger toward said cam, spacer means removably secured to both said mounting means and to an injection fluid reservoir means, said spacer means being axially bored for receiving said plunger and further having aperture means for permitting access to an adjustment collar, said adjustment collar including means which, in conjunction with said spacer means, adjusts the stroke of said plunger, said injection fluid reservoir means being axially bored for receiving said plunger, said reservoir means including injection fluid inlet and outlet communicating with a reservoir portion, and reciprocating plunger means in contact, at one end thereof, with said further ball bearing assembly means, its other end being reciprocatingly received by said reservoir portion of said reservoir means, said plunger further carrying means limiting said plungers stroke to the linear separation between one end of said adjustment collar and an adjacent web of said spacer.