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, 1977
Filed:
Aug. 11, 1975
Ralph E Bruce, Dayton, OH (US);
Production Control Units, Inc., Dayton, OH (US);
Abstract
A plurality of refrigeration units are successively charged with a liquid refrigerant which is dispensed by a positive displacement pump including a hydraulically actuated ram or piston slidably supported within a dispensing cylinder. An elongated tension coil spring extends parallel to the axis of the cylinder, and the piston carries a photosensing device which senses the helical turns of the spring when the piston is actuated to provide corresponding electrical pulses which are counted for precisely controlling the axial movement of the piston and the displacement of the refrigerant into each refrigeration unit. The length of the spring and the uniform spacing or pitch of the helical turns is automatically changed in response to changes in temperature of the refrigerant being dispensed to assure that each refrigeration unit is charged with precisely the desired weight of refrigerant regardless of changes in temperature of the refrigerant. Controls are also provided for controlling the counting of the spring turns and the displacement of the piston in response to changes in compressibility of the refrigerant with changes in temperature.