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. 13, 1993
Filed:
Jul. 30, 1991
Christopher Ferguson, Framingham, MA (US);
Joseph E Musil, Ely, IA (US);
Raytheon Company, Lexington, MA (US);
Abstract
A sonic grade control device for maintaining a leveling instrument of a paver at a constant distance from a datum. The device transmits and receives a sonic signal to provide first and second time periods corresponding to the round trip travel time of a sonic signal to the datum and a target, respectively. A distance indicating signal, corresponding to the distance between the control device and the datum, is provided in response to the first and second time periods and a stored target distance, such target distance corresponding to the distance between the control device and the target. The grade control device includes an operator actuable control for modifying the stored target distance to calibrate the control device. A reference signal is compared to the distance indicating signal to provide a control signal. The reference signal is adjustable by a predetermined increment and the control device includes an operator actuable control for modifying the predetermined increment. The position of the leveling instrument is changed in response to the control signal being greater than a predetermined, or deadband value. The control device includes a display for indicating such predetermined value and an operator actuable control for modifying such value.