Patent · US Expired

Hydraulic control devices for use with mining apparatus

US4537221A · kind A · utility

3Cited by

3References

9Claims

0Family size

Assignee

Gewerkschaft Eisenhutte Westfalia GmbH · DE

Inventors

Walter Weirich · Dortmund, DE
Michael Dettmers · Kamen, DE

Key dates

Filing date	Apr 24, 1984
Grant date	Aug 27, 1985
Priority date	—
Expiry date	Apr 24, 2004

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T137/87121
WIPO fieldCivil engineering
WIPO sectorOther fields

Abstract

A compact hydraulic control device for use with mining apparatus is composed of a housing block containing tappet-operated valves. A multi-part cam shaft serves selectively to operate the valves by displacing the tappets by manual control effected by external levers. To automatically restore the cam shaft back into a neutral position as a "dead-man's handle" restoring system use is made of a pair of piston and cylinder assemblies mounted as detachable cartridges in parallel locations within bores in the housing block and having push rods which act on a cam of the cam shaft under the action of hydraulic or pneumatic pressure medium.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.