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. 05, 1983
Filed:
Aug. 20, 1979
Donald J Haub, Champlin, MN (US);
Neil T Brown, Minneapolis, MN (US);
Keith N Krier, Tonka Bay, MN (US);
Raymond C Hawkins, Minneapolis, MN (US);
Howard N Seim, Columbia Heights, MN (US);
Tennant Company, Minneapolis, MN (US);
Abstract
An improvement for electrically driven floor maintenance apparatus including means for varying the speed of the driving motors is disclosed. Two speed ranges are provided by switching means which change the interconnection of the drive motors from series for the low speed range, and parallel for the high speed range. Within each speed range, intermediate speeds are provided by placing resistors with shunt in series with the motors. Time delay circuitry is also included to prevent immediate operation of the vehicle in the high speed of each range until the vehicle has had some time to accelerate. Additionally, means are provided for detecting whether a vehicle is rolling in a forward or reverse direction and circuits are provided to prevent the operator from driving the vehicle in an opposite direction until the vehicle has slowed down to a near stop. A deadman control is provided to prevent the energizing of the drive motors when the operator is no longer seated on the driver's seat. ///