Accession Number : ADD005199

Title :   Hydraulic Chain Jack Automatic Latch Control System.

Descriptive Note : Patent Application,


Personal Author(s) : Skaalen,Clifford I

Report Date : 16 Jun 1978

Pagination or Media Count : 30

Abstract : A chain jack utilizing two chains is operated by alternately transferring the chain load from latches incorporated within an upper latch assembly to latches incorporated within a lower latch assembly while moving the upper and lower latch assemblies away from and toward each other by alternate extension and retraction of a hydraulic ram to cause relative movement between the chain and the lower latch assembly. Actuation of the latch mechanism is controlled by hydraulic connection to a pair of four-way valves operated by a control piston having followers from the fourway valves engageable thereon. The control piston is disposed to move with the upper latch assembly while the followers are rigidly affixed to the lower latch assembly. Thus, the engagement and disengagement of the latch mechanisms with the chains are synchronized by the relative movement between the lower and upper latch assemblies. (Author)

Descriptors :   *Patent applications, *Hydraulic jacks, *Chains, Latches, Control systems

Subject Categories : Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE