BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is a fragmentary perspective view of the preferred embodiment of a window blind according to the present invention;
FIG. 2 is an exploded perspective, partly sectional view to illustrate a shaft unit of the preferred embodiment;
FIG. 3 is a partly sectional view of the preferred embodiment to illustrate rotation of a shaft member of the shaft unit in a first rotational direction;
FIG. 4 is a partly sectional view of the preferred embodiment to illustrate rotation of the shaft member of the shaft unit in a second rotational direction; and
FIG. 5 is a sectional view of the preferred embodiment to illustrate when a tubular member of the shaft unit being driven by a pushing member of the shaft unit to rotate in the second rotational direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the preferred embodiment of a window blind according to this invention is shown to include a pair of elongate slide rails 64, a shaft unit 4, a flexible screen body 61, a pair of bobbins 55, a pair of pulleys 63, a pair of ropes 65, and a clutch unit 54.
The window blind of this embodiment is applied to cover and uncover a sunroof (not shown), in a manner that will be described hereinafter.
Each of the slide rails 64 has opposite first and second rail ends 641, 642, and is formed with a rail groove 640 that extends from the first rail end 641 to the second rail end 642 of a respective one of the slide rails 64.
With further reference to FIG. 2, the shaft unit 4 includes a pair of seat members 41, a shaft member 43, a tubular member 42, and a pushing member 44. Each of the seat members 41 of the shaft unit 4 is disposed proximate to the first rail end 641 of a respective one of the slide rails 64. The shaft member 43 of the shaft unit 4 is mounted rotatably on the seat members 41. The tubular member 42 of the shaft unit 4 is sleeved rotatably around the shaft member 43 of the shaft unit 4, and is formed with an inner protrusion 421 that extends radially and inwardly therefrom. The pushing member 44 of the shaft unit 4 is disposed in the tubular member 42 of the shaft unit 4, is sleeved securely on the shaft member 43 of the shaft unit 4, and is formed with an outer protrusion 441 that extends radially and outwardly therefrom.
The screen body 61 is wound on the tubular member 42 of the shaft unit 4, and has lateral ends 611, each of which is disposed in the rail groove 604 in a respective one of the slide rails 64, and a front end 612 that interconnects the lateral ends 611 of the screen body 61.
The window blind further includes a batten 62 that is connected to the front end 612 of the screen body 61.
The bobbins 55 are disposed on opposite sides of the pushing member 44 of the shaft unit 4 and are sleeved rotatably on the shaft member 43 of the shaft unit 4.
Each of the pulleys 63 is mounted rotatably on the second rail end 642 of a respective one of the slide rails 64.
Each of the ropes 65 is wound on a respective one of the bobbins 55, is trained on a respective one of the pulleys 63, and has an end that is connected to the batten 62.
The clutch unit 54 serves to connect and disconnect the shaft member 43 of the shaft unit 4 and the bobbins 55. In this embodiment, the clutch unit 54 includes a pair of couplers 543 and a pair of springs 542. Each of the couplers 543 of the clutch unit 54 is sleeved rotatably on the shaft member 43 of the shaft unit 4 and is connected to a respective one of the bobbins 55. Each of the springs 542 of the clutch unit 54 is disposed in a respective one of the couplers 543 of the clutch unit 54, is sleeved on and is in frictional contact with the shaft member 43 of the shaft unit 4, and has an end that is connected to a respective one of the couplers 543 of the clutch unit 54.
In operation, with further reference to FIG. 3, when the shaft member 43 of the shaft unit 4 is rotated in a first rotational direction, as indicated by arrow (A), this enables the springs 542 of the clutch unit 54 to contract in radial inward directions to thereby connect the shaft member 43 of the shaft unit 4 and the bobbins 55 through the couplers 543 of the clutch unit 54, respectively. This results in rotation of the bobbins 55, winding of each of the ropes 65 on the respective one of the bobbins 55 to thereby permit the ropes 65 to pull the screen body 61, rotation of the tubular member 42 of the shaft unit 4, and unwinding of the screen body 61 from the tubular member 42 of the shaft unit 4 to thereby cover the sunroof (not shown).
With further reference to FIG. 4, when the shaft member 43 of the shaft unit 4 is rotated in a second rotational direction opposite to the first rotational direction, as indicated by arrow (B), this enables the springs 542 of the clutch unit 54 to expand in radial outward directions to thereby disconnect the shaft member 43 of the shaft unit 4 and the bobbins 55. At this time, when the shaft member 43 of the shaft unit 4 is further rotated in the second rotational direction (B), this enables the outer protrusion 441 of the pushing member 44 of the shaft unit 4 to abut against the inner protrusion 421 of the tubular member 42 of the shaft unit 4, as best shown in FIG. 5. This results in rotation of the tubular member 43 of the shaft unit 4, winding of the screen body 61 on the tubular member 42 of the shaft unit 4 to thereby uncover the sunroof (not shown), rotation of the bobbins 55, and unwinding of each of the ropes 65 from the respective one of the bobbins 55.
As best shown in FIG. 1, the window blind further includes an electric motor unit 42 that is mounted on one of the seat members 41 of the shaft unit 4, and that is operable so as to rotate the shaft member 43 of the shaft unit 4 in the first and second rotational directions (A, B), thereby permitting automated operation of the window blind of this invention.
As best shown in FIG. 2, the window blind further includes a torque transmission unit 7 that prevents slackening of the screen body 61 and the ropes 65. Since the construction of the torque transmission unit 7 is known to those skilled in the art, a detailed description of the same will be dispensed with herein for the sake of brevity.
It is noted that, in an alternative embodiment, the window blind of this invention is applied to a vertical window (not shown), and is dispensed with the slide rails 64, the pulleys 63, and the torque transmission unit 7.
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.
Patent Application
20080006373
