Control Device for folding/unfolding Window Shade

• US 20110290429A1
• Filed: 05/28/2010
• Published: 12/01/2011
• Est. Priority Date: 05/28/2010
• Status: Abandoned Application

• Current Assignee: Li-Ming Cheng
• Original Assignee: Li-Ming Cheng
• Inventors: Cheng, Li-Ming
• Application Number:
  US12/789,860
• Publication Number:
  US 20110290429A1
• Time in Patent Office: Days
• US Class Current: 160/84.02
• CPC Class Codes: E06B 2009/2627 Cellular screens, e.g. box or honeycomb-like
• CPC Class Codes: E06B 2009/3222 Cordless, i.e. user interface without cords
• CPC Class Codes: E06B 9/262 with flexibly-interconnected horizontal or vertical strips; Concertina blinds , i.e. upwardly folding flexible screens
• CPC Class Codes: E06B 9/322 Details of operating devices, e.g. pulleys, brakes, spring drums, drives operating devices E06B9/68 ; devices of general interest specially adapted or mounted for storing and repeatedly paying-out and re-storing lengths of material B65H75/34

Abstract

A control device for folding/unfolding a window shade includes a casing rotatably receiving first and second driving wheels around which a pull cord and a tying cord are wound. The first driving wheel includes a first gear and a pressing member. The second driving wheel includes a second gear and an auxiliary gear. A clutch unit is located between the first and second driving wheels and includes a first end releasably engaged with the auxiliary gear on the second driving wheel and a second end abutting the pressing member. A transmission gear is slideably received in the casing. The pull cord is pullable to a desired extent to control the transmission gear to mesh with the first gear or both of the first and second gears, achieving folding or unfolding of the window shade.

Claims

1. A control device for folding/unfolding a window shade comprising:

a casing including a compartment, a guide slot, and first and second cord outlets in communication with the compartment;

a first driving wheel including a first body, a first gear, and a pressing member, with the first body rotatably received in the compartment and including a first cord groove, with a pull cord releasably wound in the first cord groove, with the pull cord including an end extending out of the casing via the first cord outlet, with the first gear fixed on a side of the first body, with the pressing member mounted on an outer periphery of the first body and including an arm;

a second driving wheel including a second body, a second gear, and an auxiliary gear, with the second body rotatably received in the compartment and including a second cord groove, with a tying cord releasably wound in the second cord groove, with the tying cord including an end extending out of the casing via the second cord outlet, with the second gear and the auxiliary gear respectively fixed on two opposite sides of the second body;

a clutch unit pivotably received in the compartment and located between the first and second driving wheels, with the clutch unit including a first end releasably engaged with the auxiliary gear, with the clutch unit including a second end abutting the arm of the pressing member; and

a transmission gear received in the compartment and meshed with the first gear, with the transmission gear slideable along the guide slot to a position engaged with the first and second gears by pulling the pull cord,

with the pull cord being pullable to a first extent for unfolding the window shade while the transmission gear merely meshed with the first gear,

with the pull cord being pullable to a second extent to move the transmission gear to the position engaged with the first and second gears, folding the window shade.

2. The control device as claimed in claim 1, with the casing including a base and a lid, with the base including a bottom plate and a sidewall surrounding a perimeter of the bottom plate, defining the compartment between the bottom plate and the sidewall, with the base including a mounting opening in which the lid is mounted.

3. The control device as claimed in claim 2, with the base including a stop wall, with a passageway formed between the stop wall and the sidewall, with the passageway including a first end in communication with the compartment and a second end in communication with the first cord outlet in the sidewall, with the pull cord extending through the passageway.

4. The control device as claimed in claim 3, with the bottom plate including an inclined guide face formed in the passageway, with the inclined guide face inclining from the first end towards the second end of the passageway, with a spacing between the first end of the passageway and the lid being larger than a spacing between the second end of the passageway and the lid.

5. The control device as claimed in claim 4, with the bottom plate including a rack portion formed in the inclined guide face.

6. The control device as claimed in claim 5, further comprising:

a roller received in the passageway, with the roller being rollable between the first and second ends of the passageway.

7. The control device as claimed in claim 6, with the roller including first and second ends, with a toothed section formed on an outer periphery of the first end of the roller and meshed with the rack portion, with a neck formed on the second end of the roller and having an outer diameter smaller than that of the toothed section, with the neck having a smooth outer periphery.

8. The control device as claimed in claim 2, with the casing further including a partitioning board detachably mounted in the compartment and parallel to the lid and the bottom board, with the partitioning board dividing the compartment into a first compartment section and a second compartment section.

9. The control device as claimed in claim 8, with the guide slot defined in the partitioning board and located between the first and second driving wheels.

10. The control device as claimed in claim 3, with the first body further including an annular groove, with the annular groove and the first cord groove being defined in the outer periphery of the first body, with the pressing member received in the annular groove.

11. The control device as claimed in claim 10, with the pressing member being a torsion spring.

12. The control device as claimed in claim 2, with the clutch unit including an engaging member pivotably mounted to the base, with the engaging member including a catch releasably engaged with the auxiliary gear of the second driving wheel.

13. The control device as claimed in claim 12, with the engaging member further including a driving portion and an engagement portion, with the driving portion and the engagement portion being formed on an outer periphery of the engaging member, with the arm of the pressing member pressing against the driving portion.

14. The control device as claimed in claim 12, with the clutch unit further including a resilient return element pivotably mounted to the base, with the resilient return element including a first end abutting the engagement portion of the engaging member and a second end abutting the sidewall.

15. The control device as claimed in claim 1, with the first driving wheel being rotated to disengage the clutch unit from the second driving wheel and thus to allow rotation of the second driving wheel while the pull cord is pulled to the first extent.

16. The control device as claimed in claim 1, with the second extent being larger than the first extent, and the first driving wheel being rotated to disengage the clutch unit from the second driving wheel while the pull cord is pulled to the second extent.