# US 5,706,771 A · Hydraulic element assembly

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- Number: US 5,706,771 A
- Document ID: US5706771A
- Status: Granted
- Kind: A
- Application number: 08/773,238
- Filed: 1996-12-23
- Granted: 1998-01-13
- Earliest claimed: 1996-12-23
- Assignees: General Motors Corporation
- Inventors: Paul Robert Van Heyningen; Oscar Alfredo Estratti; Michael Edward Mc Carroll; Antonio St. Clair Lloyd Williams; Daniel Patrick O 'Neill; Donald R. Smith; John Joseph Burns
- Web page: https://patentgrep.com/patent/US5706771A

## CPC

- F01L 1/2411: {by means of a hydraulic adjusting device located between the valve stem and rocker arm}
- F01L 1/46: Component parts, details, or accessories, not provided for in preceding subgroups
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES

## Abstract

A valve actuation assembly for an internal combustion engine is disclosed in which a rotatable rocker arm assembly is actuated by an engine driven camshaft to move a poppet valve reciprocably. The rocker arm assembly includes a hydraulic lash adjuster for disposition between the rocker arm and the valve stem. The lash adjuster includes an actuator at one end having an axially extending neck which terminates in an enlarged head. The enlarged head engages a foot assembly which includes a disk having a socket in which the head is positioned. A retainer ring is disposed in the socket and includes a wall portion which operates to establish an interference fit with the socket so as to fix the ring in the socket and a radially inwardly extending flange member which operates to define an opening through which the actuator neck extends but having a diameter less than that of the enlarged head portion of the actuator to thereby prevent removal of the head from the socket.

## Claims

### Claim 1

A hydraulic lash adjuster for disposition between a rocker arm and a valve stem of an internal combustion engine comprising a body having an actuator disposed at a first end, said actuator comprising an axially extending neck terminating in an enlarged head portion, said lash adjuster further comprising a foot assembly comprising a disc member having a first surface which includes a socket and a second, flat surface, said socket configured to receive said enlarged head portion therein, and an annular retainer ring disposed in said socket said retainer ring including an axially extending cylindrical wall portion operable to establish an interference fit with said socket to fix said retainer therein, said retainer having at its upper end a radially inwardly extending flange member operable to define an opening through which said axially extending neck extends, said opening having a diameter smaller than said enlarged head portion of said actuator, said retainer operable to prevent egress of said enlarged head from said socket.

### Claim 2 (depends on 1)

A hydraulic lash adjuster, as defined in claim 1, said opening defined by said inwardly extending flange member of said retainer having a diameter larger than the diameter of said actuator neck and operable to allow angular movement of said foot relative to said enlarged head portion.

### Claim 3 (depends on 1)

A hydraulic lash adjuster, as defined in claim 1, said diameter of said actuator neck including an axial taper which increases from said lash adjuster body to said enlarged head portion, said axial taper operable to minimize lateral movement of said foot assembly relative to said enlarged head portion when said foot assembly is axially unsupported relative thereto.