Automatic hand dryer
First Claim
1. An automatic hand dryer, comprising:
- a mounting plate adapted for attachment to a wall parallel to the surface of the wall;
a fan housing attached to the mounting plate and having an air inlet and a downwardly-directed air outlet for directing air into a zone;
a motor attached to the fan housing;
a squirrel cage fan mounted in the fan housing so as to be driven by the motor, the axis of rotation of the fan being perpendicular to said mounting plate;
a heating element disposed in the fan housing for heating the air exhausted through the outlet into the zone;
sensor means for sensing the presence of a user at the zone outside the outlet of the hand dryer; and
control circuit means responsive to the sensor means to control operation of the motor and heating element.
1 Assignment
0 Petitions
Accused Products
Abstract
An automatic hand dryer contains a heating element and a motor which drives a squirrel cage fan. The fan exhausts air past the heating element to a downwardly-directed outlet. A base or mounting plate is adapted for flush mounting to a wall. The axis of the fan is perpendicular to the base plate and wall to which the dryer is attached. A control or sensing circuit emits signals to a detection zone beneath the outlet and monitors the zone for reflected signals indicative of a user'"'"'s presence. The circuit operates to energize and deenergize the power circuit to the fan motor and heating element. Upon detection for a predetermined period, the circuit energizes the power circuit. The control circuit deenergizes the power circuit upon interruption of the reflected signals for a predetermined period, or after a predetermined maximum time period of continuous detection. Under the latter condition, the stimulus reflecting the emitted signals must be removed from the detection zone to reactivate the control circuitry. Any incremental interruption in the reflected signal which does not exceed the period of permitted interruption, restarts the commencement of the timing of the maximum period of continuous detection.
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Citations
16 Claims
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1. An automatic hand dryer, comprising:
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a mounting plate adapted for attachment to a wall parallel to the surface of the wall; a fan housing attached to the mounting plate and having an air inlet and a downwardly-directed air outlet for directing air into a zone; a motor attached to the fan housing; a squirrel cage fan mounted in the fan housing so as to be driven by the motor, the axis of rotation of the fan being perpendicular to said mounting plate; a heating element disposed in the fan housing for heating the air exhausted through the outlet into the zone; sensor means for sensing the presence of a user at the zone outside the outlet of the hand dryer; and control circuit means responsive to the sensor means to control operation of the motor and heating element. - View Dependent Claims (2, 3, 4, 5, 6, 9, 10)
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7. In an apparatus having an electrical device, sensing means for detecting the presence of a user and control means responsive to the sensing means for controlling operation of the electrical device, the control means having at least an "OFF" delay interval and a timing means for timing the period of continuous detection, an improved method of controlling the energization of the electrical device comprising the steps of:
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(a) monitoring a detection zone with the sensing means for the presence of a user; (b) (c) energizing the electrical device for an indeterminate period of time; (d) resetting the timing means to zero upon interruption of detection; (e) staring the "OFF" delay interval upon interruption of detection; (f) maintaining energization of the electrical device during the "OFF" delay interval; (g) maintaining energization of the electrical device after the "OFF" delay interval if detection recurs before completion of that interval; (h) de-energizing the electrical device upon completion of the "OFF" delay interval in the absence of a recurrence of detection; and (i) de-energizing the electrical device when detection has been continuous for a predetermined period even though a user is still present in the detection zone and detection continues. - View Dependent Claims (8, 11, 12, 13, 14, 15, 16)
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Specification