Ultrasonic sensor for detecting the dispensing of a product
View Patent ↗A vending machine includes a vend sensor for detecting a completion of a vend operation. The vend sensor includes an electronic circuit connected to first and second sound elements positioned on opposing sides of a product delivery chute of the vending machine. The first sound element directs a sound beam across the product delivery chute where it is received by the second sound element. During a vend operation, a product container is guided to the product delivery chute to be dispensed to a consumer. As the container passes through the product delivery chute, the sound beam is interrupted, thereby signaling the completion of a vend operation. Each of the first and second sound elements is provided with a cone that focuses the sound beam so as to limit interruptions stemming from outside sound sources.
1. A vending machine comprising:
a product storage area;
a vend mechanism to dispense a product from the product storage area;
a delivery chute to receive a product dispensed from the product storage area;
a control unit to operate the vend mechanism; and
a sensor system to sense a presence of an object in the delivery chute and to signal the presence to the control unit, wherein the sensor system includes
a sound transmitter,
a sound receiver,
a circuit to receive a signal from the sound receiver, the circuit adapted to detect an amplitude of the received signal and to detect a phase of the received signal, wherein the circuit produces a signal in response to the received signal indicating the presence of the object in the delivery chute.
2. The vending machine of claim 1 , wherein at least one of the sound transmitter and the sound receiver comprises a housing that provides a water resistant barrier for an element of the at least one sound transmitter and sound receiver.
3. The vending machine of claim 1 , wherein at least one of the sound transmitter and the sound receiver comprises a housing that aids in positioning the at least one sound transmitter and sound receiver in the delivery chute.
4. The vending machine of claim 3 , wherein the housing comprises at least one of an angled face portion and a positioning ear.
5. The vending machine of claim 1 , wherein the circuit produces the signal indicating the presence of the object in the delivery chute in response to detecting from the phase of the received signal that the received signal is not periodic.
6. The vending machine of claim 1 , wherein the circuit produces the signal indicating the presence of the object in the delivery chute in response to detecting from the amplitude of the received signal that a strength of the received signal is below a predetermined threshold.
7. The vending machine of claim 1 , wherein the control unit is adapted to terminate a vend operation in response to the signal from the sensor system indicating the presence of an object in the delivery chute during the vend operation.
8. The vending machine of claim 1 , wherein the control unit is adapted to activate a pilfering protection mechanism in response to the signal from the sensor system indicating the presence of an object in the delivery chute when the vending machine is not performing a vend operation.
9. The vending machine of claim 1 , wherein the control unit is adapted to indicate that a product is sold out in response to the signal from the sensor system.
10. A method of operating a vending machine, the method comprising:
in a delivery chute of the vending machine, sending a sound beam from a sound transmitter to a sound receiver;
detecting an amplitude of a signal from the sound receiver;
detecting a phase of a signal from the sound receiver; and
producing a signal indicating a presence of an object in the delivery chute in response to the signal from the sound receiver.
11. The method of claim 10 , wherein the signal indicating a presence of an object in the delivery chute is produced in response to detecting from the phase of the received signal that the received signal is not periodic.
12. The method of claim 10 , wherein the signal indicating a presence of an object in the delivery chute is produced in response to detecting from the amplitude of the received signal that a strength of the received signal is below a predetermined threshold.
13. The method of claim 10 , further comprising terminating a vend operation in response to the signal indicating the presence of an object in the delivery chute during the vend operation.
14. The method of claim 10 , further comprising activating a pilfering protection mechanism in response to the signal indicating the presence of an object in the delivery chute when the vending machine is not performing a vend operation.
15. The method of claim 10 , further comprising indicating that a product is sold out in response to the signal indicating the presence of an object in the delivery chute.
16. A sensor system to sense a presence of an object in a delivery chute of a vending machine, wherein the sensor system includes
a sound transmitter,
a sound receiver,
a circuit to receive a signal from the sound receiver, the circuit adapted to detect an amplitude of the received signal and to detect a phase of the received signal, wherein the circuit produces a signal in response to the received signal indicating the presence of the object in the delivery chute.
17. The sensor system of claim 16 , wherein at least one of the sound transmitter and the sound receiver comprises a housing that provides a water resistant barrier for an element of the at least one sound transmitter and sound receiver.
18. The sensor system of claim 16 , wherein at least one of the sound transmitter and the sound receiver comprises a housing that aids in positioning the at least one sound transmitter and sound receiver in the delivery chute.
19. The sensor system of claim 16 , wherein the circuit produces the signal indicating the presence of the object in the delivery chute in response to detecting from the phase of the received signal that the received signal is not periodic.
20. The sensor system of claim 16 , wherein the circuit produces the signal indicating the presence of the object in the delivery chute in response to detecting from the amplitude of the received signal that a strength of the received signal is below a predetermined threshold.