Control system for electrical cord reel

• US 8,995,099 B2
• Filed: 08/03/2012
• Issued: 03/31/2015
• Est. Priority Date: 08/05/2011
• Status: Active Grant

• Current Assignee: Great Stuff, Inc.
• Original Assignee: Great Stuff, Inc.
• Inventors: Tracey, James B. A., Rosenau, Mark, Hill, Joseph M. III, Tracey, Johnathan R.
• Primary Examiner(s): KIM, SANG K
• Application Number:
  US13/566,715
• Publication Number:
  US 20130032654A1
• Time in Patent Office: 970 Days
• Field of Search: 361/42, 324/511
• US Class Current: 361/42
• CPC Class Codes: B65H 2553/41 Photoelectric detectors
• CPC Class Codes: B65H 2701/34 electric cords or electric power cables
• CPC Class Codes: B65H 75/4463 Swivelling attachment
• CPC Class Codes: B65H 75/4471 Housing enclosing the reel
• CPC Class Codes: B65H 75/4484 Electronic arrangements or adaptations for controlling the winding or unwinding process, e.g. with sensors
• CPC Class Codes: H02G 11/02 using take-up reel or drum
• CPC Class Codes: H02G 3/02 Details

Abstract

In an electrical cord reel, a rotatable member can rotate about a winding axis to spool and unspool a linear material. An input power connector can couple to an electrical power source. An output power connector on the rotatable member can couple to an electrical cord at least partially wound about the rotatable member. A switch is adjustable to allow or prevent electrical current flow from the input power connector to the output power connector. In an aspect, the electrical cord reel includes an electric cord comprising a first power wire, a second power wire, and a signal wire. A method of controlling the electric cord spool system includes energizing the first power wire and the signal wire. The method further includes determining a continuity of the signal wire. The method further includes de-energizing the first power wire when determining discontinuity of the signal wire.

Claims

1. An electric cord comprising:

a hot wire comprising input and output terminals, the hot wire configured to receive a current at the input terminal and to provide the current at the output terminal;

a neutral wire comprising input and output terminals, the neutral wire configured to complete a circuit in conjunction with the hot wire;

a signal wire configured to carry a signaling current; and

a first switch configured to selectively couple the signal wire to both the input and output terminals of the neutral wire.

2. The electric cord of claim 1, wherein the input terminal of the hot wire is configured to receive an alternating voltage at approximately 120 V RMS and approximately 60 Hz.

3. The electric cord of claim 1, further comprising an electric cord control system comprising:

a second switch configured to selectively connect the hot wire with a power source in a closed state, and to disconnect the hot wire from the power source in an open state;

a controller configured to control the second switch and to provide a current to the signal wire;

a first resistor electrically coupling the signal wire and the neutral wire, and configured to allow a first current to flow from the signal wire to the neutral wire;

a continuity detector electrically coupled to the signal wire and configured to provide a continuity detection signal to the controller when the first current is flowing through the signal wire,

wherein the controller is further configured to open the second switch when it fails to receive the continuity detection signal from the continuity signal detector.

4. The electric cord of claim 3, wherein:

the first switch is configured to selectively couple the signal wire and the neutral wire, in parallel with the first resistor, and to allow a second current to flow between the signal wire and the neutral wire; and

the electric cord control system further comprises a signaling detector electrically coupled to the signal wire and configured to provide a signaling detection signal to the controller when the second current is flowing through the signal wire.

5. The electric cord of claim 4, wherein the controller is further configured to toggle the second switch, between the open and closed state, when it receives the signaling detection signal from the signaling detector.

6. The electric cord of claim 4, further comprising:

a spool member onto which the electric cord can be spooled;

a motor configured to rotate the spool member in at least one of a spooling direction and an unspooling direction, based on a signal from the controller;

wherein the controller is further configured to;

detect the state of the second switch,

open the second switch when the switch is closed and the controller receives the signaling detection signal from the signaling detector; and

control the motor to rotate in the spooling direction when the second switch is open and the controller receives the signaling detection signal from the signaling detector.

7. The electric cord of claim 6, wherein the controller is further configured to:

detect an unspooled length of the electrical cord;

control the motor to rotate in the spooling direction at a first speed when the unspooled length is at least a threshold length and the controller receives the signaling detection signal from the signaling detector.

8. The electric cord of claim 7, wherein the controller is further configured to control the motor to rotate in the spooling direction at a second speed when the unspooled length is less than the threshold length and the controller receives the signaling detection signal from the signaling detector, the second speed being lower than the first speed.

9. The electric cord of claim 8, wherein the controller is further configured to set the unspooled length of the electrical cord, in a memory, as the threshold when the controller receives the signaling detection signal from the signaling detector in accordance with a signaling pattern.

10. The electric cord of claim 9, wherein the signaling pattern comprises continuously receiving the signaling detection signal for a first length of time.

11. The electric cord of claim 9, wherein the signaling pattern comprises intermittently receiving the signaling detection signal a first number of times within a first length of time.

12. The electric cord of claim 6, wherein the controller is further configured to refrain from controlling the motor to rotate in the spooling direction when the second switch is closed.

13. The electric cord of claim 4, wherein the signaling detector comprises:

a light emitting diode in series with the signal wire; and

a photodetector electrically coupled to the controller and configured to provide the signaling detection signal to the controller when the photodetector detects light emitted from the light emitting diode.

14. The electric cord of claim 13, further comprising a current threshold circuit in parallel with the signaling detector, the current threshold circuit comprising:

a second diode having a first and second end;

a second resistor having a first and second end, the first end electrically coupled to a first end of the light emitting diode, the second end electrically coupled to the first end of the second diode; and

a third resistor having a first and second end, the first end electrically coupled to a second end of the light emitting diode, the second end electrically coupled to the second end of the second diode.

15. The electric cord of claim 14, wherein the difference between a threshold voltage of the light emitting diode and a threshold voltage of the second diode is greater than the first current times the sum of the resistances of the second and third resistors.

16. The electric cord of claim 14, wherein the difference between a threshold voltage of the light emitting diode and a threshold voltage of the second diode is less than or equal to the second current times the sum of the resistances of the second and third resistors.

17. The electric cord of claim 3, wherein the continuity detector comprises:

a light emitting diode in series with the signal wire; and

a photodetector electrically coupled to the controller and configured to provide the continuity detection signal to the controller when the photodetector detects light emitted from the light emitting diode.

18. The electric cord of claim 1, further comprising a first resistor electrically coupling the signal wire and the neutral wire, in parallel with the first switch, and configured to allow a first current to flow from the signal wire to the neutral wire.

19. The electric cord of claim 18, wherein, when the first switch is closed, the signal wire and neutral wire are configured to carry a greater current than when the first switch is open.

20. The electric cord of claim 18, wherein the first resistor allows a controller to detect a continuity of the electrical cord.

21. The electric cord of claim 1, wherein the signal wire is configured to convey a signal to a controller from an end of the electrical cord.