Abstract: A hydraulic lash adjuster of the type in which the plunger assembly (15) includes a ball plunger element (50), and defines a valve opening (57) in the lower plunger member (19). A check valve member (53) is seated in the valve opening (57), for opening the valve opening in response to a relative decrease in the pressure in a high pressure chamber (23). The ball plunger element (50) includes a metering valve element (45) movable between an outward position (FIG. 1) and an inward position (FIG. 2). An elongated member (65) is fixed to move with the metering element (45), and includes a lower end (67) juxtaposed the valve opening (57). When the metering element (45) is in its inward position, the lower end (67) engages the check ball (53) and lifts it from the valve opening, thus facilitating assembly of the lash adjuster, filled with fluid, into an engine.

Abstract: A hydraulic lash adjuster having a body (11) defining a blind bore (13) and a fluid port (35) in communication with a source of fluid pressure. Upper and lower plunger elements (17,19) are disposed within the body and define a low pressure fluid chamber (21). The upper end portion (53) of the lower plunger element (19) defines a series of openings (55) providing fluid communication from the bore (13) into the chamber (21). The bore (13) and the upper plunger element (17) define a radial clearance sufficient that the clearance and the openings (55) comprise substantially the only fluid path from the fluid port (35) to the chamber (21). The invention reduces the machining of the body (11) and the upper plunger (17) which are normally required, thus substantially reducing the cost of the lash adjuster.

Abstract: A hydraulic lash adjuster of the type including a ball plunger (61) defining a passage (63), or a body portion (85) defining a passage (87). A metering valve is disposed in the passage, and in accordance with the invention (FIGS. 2-4), a shank portion (77) of the metering pin (73) defines a metering passage (81). During normal operation, pressure in the low pressure chamber (21) biases the metering pin (73) upward, to a position in which fluid can flow from the chamber (21), through the metering passage (81), to the external surface (71) of the ball plunger (61). When pressure in the chamber (21) is very low, or negative, a head portion (75) is disposed against a seat (69) in the manner of a check valve. The up and down movement of the pin (73) prevents the metering passage (81) from becoming plugged with contaminants.

Abstract: A hydraulic roller tappet for an internal combustion engine wherein the tappet body is formed of hardenable cast iron, the roller axle is formed of a through hardened steel and wherein the axle bores in the body and the axle are dimensioned such that the axle is in floating relationship with the bores. In a preferred embodiment the axle is axially retained by retaining rings received in grooves formed in the body.