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. 26, 2011
Filed:
Mar. 31, 2008
Mark R. Webster, Hubertus, WI (US);
Mark R. Webster, Hubertus, WI (US);
Pflow Industries, Inc., Milwaukee, WI (US);
Abstract
A shopping cart conveyor system is designed to shut the system down in the event that a shopping cart becomes jammed. The system includes a track operable to guide a shopping cart between a first location and a second location, and a drive assembly for moving a shopping cart along the track. The drive assembly includes engagement members movable relative to the track and operable to engage and move a shopping cart from the first location to the second location, and a drive motor (e.g., an electric motor) operable to provide movement to the engagement members. A force sensor detects a parameter (e.g., motor current) of the drive assembly corresponding with a force required to move the engagement members. A controller receives information regarding a frequency of change in the parameter and compares that information to a known value (e.g., a frequency of the engagement members). Preferably, the controller is programmed to stop the drive motor when the frequency of change of the parameter falls within a certain range of the parameter (e.g., frequency of the engagement members).