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:
Jul. 04, 1989
Filed:
Apr. 08, 1987
Gregory S Didier, Fort Wayne, IN (US);
James L Roussey, Fort Wayne, IN (US);
Navistar International Transportation Corp., Chicago, IL (US);
Abstract
A failure warning device is provided for use with an auxiliary pump unit made ready by either an ignition-on signal or a brake-on signal and activated by a pump-failure signal. The failure warning device has a monitor circuit coupled to a warning circuit. For maintaining reliability of the auxiliary pump unit, the module circuitry is wired as a monitor not including circuit components of the auxiliary pump unit. It has a first input coupled to a common ready signal produced by the pump unit and a second input coupled to a motor terminal of the pump unit. The monitor circuit responds to failure-related states of the ready signal and the motor terminal impedance and voltage by generating an anomaly signal. The alarm circuit switches on an alarm, such as a buzzer and light, when it receives both the ignition-on and anomaly signals. The monitor circuit can include a circuit for generating the anomaly signal when a comparator detects a difference between the brake-on signal and a simultaneously activated brake stop light signal. The monitor can also include a circuit to activate the alarm if a brake circuit detector senses a brake circuit failure.