Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Referring to
The cord-winding device of the present invention comprises a hollow fixed seat 3, first and second reel members 421, two first gears 422, two torsion springs 6, 7, a synchronizing wheel unit 4, and a press unit 5.
The fixed seat 3 is provided on the bottom rail 24, and includes a bottom casing 31, a top cover 32 screwed to the bottom casing 31 and cooperating with the same to define a chamber (not shown), and two spaced-apart second shafts 34 formed on the bottom casing 31 and located within the chamber.
The first and second reel members 421 are sleeved rotatably and respectively on the second shafts 34, and are adapted to wind and unwind the movable ends of the cords 23, respectively. The first and second reel members 421 are identical in size.
The first gears 422 are sleeved rotatably and respectively on the second shafts 34, and are adhered coaxially and respectively to the first and second reel members 421 for simultaneous rotation. The first gears 422 are identical in size.
The synchronizing wheel unit 4 includes a roller 412, a second gear 413, a third gear 411, and a first shaft 33 formed on the bottom casing 31 between the two second shafts 34 and located within the chamber. The roller 412 and the second and third gears 413, 411 are sleeved coaxially and rotatably on the first shaft 33. The second gear 413 is disposed between and meshed with the first gears 422.
The press unit 5 is mounted on the fixed seat 3 between the synchronizing wheel unit 4 and the top cover 32. The press unit 5 includes a press plate 51 and a compression spring 52. The press plate 51 has a press end 511, an engaging end opposite to the press end 511 and having an engaging member 512, and an elongated through hole 513 formed between the press end 511 and the engaging end. The engaging member 512 of the press plate 51 is provided with a tongue 5121 to engage releasably the third gear 411 of the synchronizing wheel unit 4 and to stop rotation of the synchronizing wheel unit 4. The first shaft 33 extends through the through hole 513. The compression spring 52 is disposed in the through hole 513, and has two opposite ends abutting respectively against the first shaft 33 and one edge of the press plate 51 defining the through hole 513.
Each of the torsion springs 6, 7 is wound around the respective second shaft 34, and has one end 61, 71 connected to the roller 412 so that the roller 412 can pull the torsion springs 6, 7 against spring forces of the torsion springs 6, 7. The torsion springs 6, 7 are therefore connected coaxially and respectively to the first and second reel members 421 for urging the first and second reel members 421 to rotate in a winding direction. Each torsion spring 6, 7 is located between one of the first gears 422 and the bottom casing 31.
When the press unit 51 is depressed, the tongue 5121 of the engaging member 512 of the press plate 51 is moved away from the third gear 411, as best shown in FIG. 6. As such, the window blind 2 can be raised and lowered. At this time, the compression spring 52 is in a compressed state. When the press plate 51 is released, the tongue 5121 of the engaging member 512 is biased by a restoring force of the compression spring 52 to move toward the third gear 411 so as to mesh with and engage the same, as best shown in
With reference to
With reference to
With reference to
Therefore, the cord-winding device of the present invention not only has a good positioning effect, through the presence of the synchronizing wheel unit 4, the first gears 422 can be rotated simultaneously with the second gear 413 of the synchronizing wheel unit 4, so that the cords 23 can be wound and unwound by equal amounts. Hence, when the window blind 2 is raised or lowered, opposite sides of the slats 22 remain even.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.