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:
Mar. 26, 1985
Filed:
Jun. 28, 1983
Sture Siby, Vaster.ang.s, SE;
ASEA Aktiebolag, Vaster.ang.s, SE;
Abstract
Compensation for external and internal pressure variations in hermetically closed load cells is achieved using three parallel diaphragms vacuum-tightly attached between a force-transmitting member and a surrounding housing. An internal diaphragm is located adjacent the transducer space, a preferably equally large external diaphragm is located adjacent the atmospheric pressure, and an intermediate diaphragm is located therebetween, the intermediate diaphragm being considerably larger than the other two diaphragms. The space between the external diaphragm and the intermediate diaphragm is connected to the transducer space and the space between the internal diaphragm and the intermediate diaphragm is connected to the atmospheric pressure. Any difference between the pressure in the transducer space and the atmospheric pressure will cause forces with the same direction for the internal diaphragm and the external diaphragm but with the opposite direction for the intermediate diaphragm, and with a suitable area of the latter, therefore, an equilibrium of forces can be achieved independently of the pressure variations.