The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 30, 1989
Filed:
May. 06, 1987
Applicant:
Inventor:
Paul Schmidt, 5940 Lennestadt 1 (Saalhausen), DE;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F15B / ;
U.S. Cl.
CPC ...
91468 ; 137469 ;
Abstract
In a pneumatic ram boring machine for laying pipelines without trenching, which is connected to a source of compressed air by a hose, a valve that suddenly opens automatically at a predetermined pressure is arranged upstream of the striker piston. On opening the valve a pressure wave results which reaches the impact piston almost undamped and prevents it from stopping at a dead center position and not starting.