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:
Apr. 28, 1998
Filed:
Jan. 20, 1995
Daniel E Peterson, Northfield, MN (US);
Dana R Lonn, Minneapolis, MN (US);
Walter J Petersen, Eden Prairie, MN (US);
The Toro Company, Minneapolis, MN (US);
Abstract
A leak detector apparatus 10 is disclosed which measures changes in fluid level in a tube 54 substantially located within a reservoir 29 of hydraulic fluid. The tube 54 has a first end which is open to the atmosphere and a second end which is submerged in the hydraulic fluid. The reservoir 29 is selectively sealed, therefore changes in the volume of the fluid within the reservoir 29 cause the fluid level within the tube 54 to change in accordance with the principles of a manometer. A measuring device is utilized to determine the level of the fluid within the tube 54, wherein the measurement device can include a float 22 having a magnet 23 located thereon interacting with a linear array of Hall effect sensors 24. A controllable venting valve 28 is provided through the reservoir 29 to equalize the pressure within the tank with the external ambient pressure. The opening and closing of the venting valve 28 is controlled by an electronic controller device 30 that uses float position and hydraulic fluid temperature as inputs, among others. Accordingly, the float position can be reset within the tube to extend the range, thereby creating a virtual column.