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:
Dec. 28, 1999
Filed:
Jun. 25, 1997
Paul G Angott, Bloomfield Hills, MI (US);
Thomas G Xydis, Ann Arbor, MI (US);
Other;
Abstract
A programmable lawn mower assembly (10) including a carriage (12) supporting a mower central processing unit (CPU) (24) for controlling the drive motors (18) to control the direction of movement of the carriage (12). The assembly (10) includes first and second locating transmitters to be disposed on posts in spaced positions about the lawn with each locating transmitter simultaneously transmitting a radio frequency signal which travels at a first velocity and an audio signal which travels at a second velocity slower than said first velocity. A carriage receiver (50, 52) is disposed on the carriage (12) for receiving the radio and audio signals from the locating transmitters and for providing signals to the CPU (24) for determining the position of the carriage (12) relative to the locating transmitters by measuring the time between said radio and audio signals from each locating transmitter. The CPU (24) includes a sequence code circuit (57) for transmitting coded signals from the carriage transmitter (54) to the locating transmitters and each locating transmitter includes a code circuit (58) for receiving and identifying the its coded signal and for directing the locating transmitter to simultaneously send the first and second signals in response to the coded signal, each locating transmitter having its own coded signal. The system also includes wake-up circuits and acknowledgment circuits.