Patent ID: 7509187
Filing Date: 2009-03-24
Classification: A61G

Abstract:
1. A wheelchair lift comprising: a lift having first and second upper lifting arms positioned substantially parallel to one another, each upper lifting arm having a first end and a second end, the lift also having first and second lower lifting arms, the first lower lifting arm connected to the second end of the first upper lifting arm and the second lower lifting arm connected to the second end of the second upper lifting arm, a pivot located between the first ends of the first and second upper lifting arms, and a platform connected to the first and second lower lifting arms and movable between a first lower height and a second higher height; a rotary position sensor mounted at the pivot and configured to generate an analog output signal that varies with the position of the platform and includes information related to a lift motion and how quickly the lift motion occurs; a ground detect sensor configured to sense contact of the platform with a solid surface and to output a signal indicative of the same; a controller configured to receive the output signal of the rotary position sensor, to determine the position of the platform based on the output of the rotary position sensor by converting the information from the rotary position sensor into a vertical distance, to change a logical state of the platform from a motion state to a paused state depending on the information from the rotary position sensor related to the lift motion and how quickly the lift motion occurs, and to receive the signal indicative of contact of the platform with a solid surface.