Patent ID: 8434709

Claim:
A towel dispenser, comprising: (a) a housing for receiving toweling comprising a roll of paper towels; (b) a sensor for sensing a leading edge of the toweling during retraction of the toweling into the housing by the motor assembly; and (c) a motor assembly configured to cause, in response to the sensing of a hand proximate the dispenser, a leading edge of the toweling to be extended from the housing, with the toweling being extended by at least a predetermined unit length beyond the point at which the sensor detects the leading edge of the toweling, and to cause the toweling to be retracted into the housing after the leading edge has been extended; (d) wherein the sensor is configured to cause the motor assembly to cease retracting the toweling into the housing as a function of the sensing of the leading edge of the toweling during retraction of the toweling into the housing; and (f) wherein the motor assembly is further configured such that the predetermined unit length, by which the toweling is extended, is set in a length learn sequence that comprises the steps of, (i) retracting the toweling until a leading edge of the toweling is sensed by the sensor, (ii) advancing the toweling a preset extended length, the preset extended length being greater than at least a distance between immediately adjacent lines of perforations in the toweling, (iii) retracting the toweling until a leading edge of the toweling is sensed by the sensor while measuring a length by which the toweling is retracted, and (iv) determining the difference between the preset extended length and the measured retracted length, the difference being the predetermined unit length.