Motorized window treatment

Patent metadata

Field	Value
Publication number	US-9605478-B2
Application number	US-201414579024-A
Country	US
Kind code	B2
Filing date	Dec 22, 2014
Priority date	Mar 11, 2011
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A motorized window treatment provides a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment includes a covering material, a drive shaft, at least one lift cord rotatably received around the drive shaft and connected to the covering material, and a motor coupled to the drive shaft for raising and lowering the covering material. The window treatment also includes a spring assist unit for assisting the motor by providing a torque that equals the torque provided by the weight on the cords that lift the covering material at a position midway between fully-open and fully-closed positions, which helps to minimize motor usage and conserve battery life if a battery is used to power the motorized window treatment. The window treatment may comprise a photosensor for measuring the amount of daylight outside the window and temperature sensors for measuring the temperatures inside and outside of the window. The position of the covering material may be automatically controlled in response to the photosensor and the temperature sensors to save energy, or may also be controlled in response to an infrared or radio-frequency remote control.

First claim

What is claimed is:

1. A motorized window treatment comprising:
a headrail having first and second opposite ends;
a covering material having a top end connected to the headrail, the covering material extending from the headrail to a bottom end;
a motor drive unit including a motor and located in the center of the headrail;
two drive shafts extending from both sides of the motor drive unit and rotatably coupled to the motor drive unit thereby allowing rotations of the motor to result in rotations of the drive shafts;
first and second lift cords, the first lift cord located proximate to the first opposite end of the headrail and the second lift cord located proximate to the second opposite end of the headrail, each lift cord rotatably received around a respective one of the drive shafts and extending vertically to the bottom end of the covering material; and
at least a first compartment and a second compartment configured to hold respective first and second batteries for powering the motor drive unit, the first and second compartments located on each side of the motor drive unit, the first compartment located between the first opposite end of the headrail and the first lift cord, and the second compartment located between the second opposite end of the headrail and the second lift cord;
wherein the motor drive unit is configured to rotate the drive shaft to adjust the bottom end of the covering material between a fully-closed position and a fully-open position in response to rotations of the drive shaft, the motor drive unit further configured to receive radio-frequency (RF) signals and to control the motor in response to the received RF signals.

2. The motorized window treatment of claim 1 , wherein the motor drive unit comprises an RF receiver configured to receive RF signals.

3. The motorized window treatment of claim 2 , further comprising a battery-powered supply that includes the first and second batteries and generates a battery voltage.

4. The motorized window treatment of claim 3 , wherein the motor drive unit is configured to monitor the magnitude of the battery voltage of the battery-powered supply, the battery-powered supply configured to enter a low-battery mode when the magnitude of the battery voltage drops below a first predetermined low-battery threshold.

5. The motorized window treatment of claim 4 , wherein the RF receiver comprises an RF transceiver configured to transmit and receive RF signals.

6. The motorized window treatment of claim 5 , wherein the motor drive unit is configured to transmit a digital message representative of the magnitude of the battery voltage.

7. The motorized window treatment of claim 5 , wherein the motor drive unit is configured to transmit a digital message indicating that the battery voltage is low via the RF signals when operating in the low-battery mode.

8. The motorized window treatment of claim 4 , wherein the RF receiver is disabled in the low-battery mode.

9. The motorized window treatment of claim 3 , wherein the at least two batteries are electrically coupled in series to generate the battery voltage to power the motor drive unit.

10. The motorized window treatment of claim 9 , wherein the motor drive unit comprises a positive-temperature coefficient thermistor coupled in series with the batteries for limiting the current drawn from the batteries.

11. The motorized window treatment of claim 3 , wherein the motor drive unit is configured to prevent the motor from operating to lower the covering material until an upper limit for the covering material is reset after a loss of power.

12. The motorized window treatment of claim 9 , wherein the at least two batteries comprise at least four D-cell batteries.

13. The motorized window treatment of claim 9 , wherein the batteries have a lifetime of approximately three years.

14. The motorized window treatment of claim 2 , wherein the motor drive unit further comprises a room-side interior temperature sensor configured to measure an interior temperature representative of the temperature in the room in which the window treatment is installed.

15. The motorized window treatment of claim 14 , wherein the motor drive unit further comprises a window-side temperature sensor configured to measure an external temperature representative of the temperature outside a window in front of which the motorized window treatment is located.

16. The motorized window treatment of claim 15 , wherein the RF receiver comprises an RF transceiver configured to transmit and receive RF signals, the motor drive unit configured to wirelessly transmit the exterior temperature via the RF signals.

17. The motorized window treatment of claim 15 , wherein the motor drive unit is configured to adjust the position of the bottom end of the covering material in response to the external and internal temperatures.

18. The motorized window treatment of claim 14 , wherein the RF receiver comprises an RF transceiver configured to transmit and receive RF signals, the motor drive unit configured to wirelessly transmit the interior temperature via the RF signals.

19. The motorized window treatment of claim 1 , wherein the motor drive unit further comprises an H-bridge drive circuit and a controller, the controller configured to provide pulse width modulated (PWM) control signals to the H-bridge drive circuit for driving the motor to control the rotational speed of the motor.

20. The motorized window treatment of claim 19 , wherein the controller is configured to ramp the rotational speed of the motor up from zero to a desired rotational speed across a ramp time when starting the motor from a stopped condition.

21. The motorized window treatment of claim 19 , wherein the PWM control signals increase in duty cycle as the covering material is raised from the midway position to the fully-open position and when the covering material is lowered from the midway position to the fully-closed position.

22. The motorized window treatment of claim 1 , wherein the motor drive unit further comprises a gear assembly operatively coupled to an output shaft of the motor and two output gears located on each side of the motor drive unit, each of the output gears coupled to one of the drive shafts, the motor drive unit further comprising a coupling member coupled between the gear assembly and the output gears allowing rotations of the output shaft of the motor to result in rotations of the drive shafts.

23. The motorized window treatment of claim 1 , wherein the motor drive unit is configured to receive the RF signals from an RF transmitter, the RF transmitter comprising one of a battery-powered remote control, an occupancy sensor, a vacancy sensor, a daylight sensor, a temperature sensor, a humidity sensor, a security sensor, a proximity sensor, a keypad, a key fob, a cell phone, a smart phone, a tablet, a personal digital assistant, a personal computer, a timeclock, an audio-visual control, a safety device, a central control transmitter, or any combination of these RF transmitters.

24. A motor drive unit for a motorized window treatment, the motorized window treatment including a covering material, a drive shaft, and at least one lift cord rotatably received around the drive shaft and extending to a bottom of the covering material for raising and lowering the covering material, the motorized window treatment further comprising a battery-powered supply having at least one battery producing a battery voltage to power t

Assignees

• Lutron Electronics Co

Inventors

• Adams Jason O
• Blair Edward J
• Cooney Andrew Karl
• Jain Soumya
• Kirby David A
• Lundy Stephen
• Mierta Justin J
• Mistarz Daniel W
• Newman Jr Robert C
• Ogden Jr Peter W
• Roe Jonathan L
• Wu Chen Ming
• Zernhelt Justin M

Classifications

• E06B2009/2625

  Pleated screens, e.g. concertina- or accordion-like · CPC title

• E06B9/68

  Operating devices or mechanisms, e.g. with electric drive · CPC title

• E06B9/70

  comprising an electric motor positioned outside the roller · CPC title

• E06B9/62

  Counterweighting arrangements (E06B9/60 takes precedence) · CPC title

• E06B9/32

  Operating, guiding, or securing devices therefor (operation of tilting bars E06B9/307) · CPC title