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:
Jun. 28, 1994
Filed:
May. 03, 1993
Applicant:
Inventors:
Harold P Sorensen, Marblehead, MA (US);
Ward H Robinson, Newton, NH (US);
Assignee:
Northern Research & Engineering Corporation, Woburn, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417254 ; 417397 ;
Abstract
A two stage free piston pneumatically operated air compressor having an integral and coaxial power piston, first stage piston and second stage piston. The discharge of the compressor first stage is the inlet for the compressor second stage. A piston-type throttling valve is used to control the speed of the reciprocating piston. The piston-type throttling valve is responsive to the pressure drop across a fixed orifice.