DOUBLE WINDING DEVICE FOR WINDOW SHADE WITHOUT PULL CORD
A double winding device for a window shade includes a head rail receiving first and second cord-winding seats. First and second movable seats are movably mounted between the first and second elastic cord-winding seats and respectively include first and second pulley units. A folding/unfolding cord is wound around the first and second pulley units and has two end sections extending through a bottom wall of the head rail and extending through two sides of a shade and fixed to a bottom of the shade. The first and second elastic cord-winding seats respectively include first and second elastic cord-winding spools. A first actuation cord is wound around the first elastic cord-winding spool and has a distal end fixed to the first movable seat. A second actuation cord is wound around the second elastic cord-winding spool and has a distal end fixed to the second movable seat.
The present invention relates to a double winding device for a window shade and, more particularly, to a double winding device that can provide a maximum folding extent in a limited space for a window shade without using a pull cord.
Window shades can provide a shield from the sun and privacy as well as decoration in rooms and can even show the taste of the users. Modern window shades generally include a pull cord to provide convenient folding/unfolding of the shade. However, the exposed length of the pull cord may strangle a child playing nearby, which problem is highlighted in countries that value human rights and demand regulations for safe window shades.
U.S. Patent Publication No. 2007/0119547 A1 (Taiwan Utility Model No. M296298) discloses a cordless window blind structure including a fixed seat and a cord-winding control unit mounted in two ends of a head rail. A movable seat is mounted in the head rail and movable between the fixed seat and the cord-winding unit. An operating cord is attached between the movable seat and the cord-winding control unit. Retrieving cords are guided through a bottom surface of the head rail. The retrieving cords are respectively led through a blind body to fix to a bottom rail at the bottommost ends. The other ends of the retrieving cords are synchronically wound around the fixed seat and the movable seat before firmly attached to the fixed seat. The bottom rail can be pushed or pulled by hands to loosen or tighten the retrieving cords and actuate the movement of the operating cord therewith to form a state of counterbalance therebetween for easy adjustment of the blind body into a desirable position.
Similarly, U.S. Pat. No. 7,398,815 B2 discloses a non-pull cord operated window blind structure including a head rail. A fixed seat and a cord-winding control unit are fixed to two ends of an accommodating channel of the head rail. A movable seat is mounted between the cord-winding control unit and the fixed seat and movable in the accommodating channel.
In the above patent and above patent publication, the retrieving cord (or collecting cord) winding extent (relative to the retrieving cord releasing extent) of the movable seat mainly depends on the spacing between the movable seat and the cord-winding control unit. The retrieving cord can be wound a plurality of rounds such that an overall displacement of the retrieving cord in the horizontal direction is equal to an overall displacement of the retrieving cord in the vertical direction. Since there is only one movable seat, longer travel and a longer period of time are required during folding/unfolding operation. Furthermore, the retrieving cord having a considerable horizontal displacement must be wound around the fixed seat and the movable seat more rounds such that the force gradually lessens, failing to provide effective transmission of force to the blind body. Due to the lack of sufficient tension, an intermediate section between two ends of one or more of the retrieving cords is liable to entangle and may cause the bottom rail and the blind body to be in a slanted state. Furthermore, it is difficult to obtain large-extent folding/unfolding of the blind body by short, horizontal displacement of the retrieving cord without increasing the horizontal travel of movable seat.
BRIEF SUMMARY OF THE INVENTIONIn a first aspect of the present invention, a double winding device is provided for a window shade without a pull cord. The double winding device includes a head rail having a compartment with a bottom wall. First and second cord holes are formed in the bottom wall of the compartment. First and second movable seats are movably mounted in the compartment. The first movable seat includes a first pulley unit, and the second movable seat includes a second pulley unit. A folding/unfolding cord is wound around the first and second pulley units. The folding/unfolding cord has two end sections respectively extending through the first and second cord holes and are adapted to be extended through two sides of a shade and fixed to a bottom of the shade. First and second elastic cord-winding seats are mounted in the compartment. The first movable seat is located between the first elastic cord-winding seat and the second movable seat. The second movable seat is located between the second elastic cord-winding seat and the first movable seat. The first and second elastic cord-winding seats respectively include a first elastic cord-winding spool and a second elastic cord-winding spool. A first actuation cord is wound around the first elastic cord-winding spool and has a distal end fixed to the first movable seat. A second actuation cord is wound around the second elastic cord-winding spool and has a distal end fixed to the second movable seat.
In a second aspect of the present invention, a double winding device includes a head rail having a compartment with a bottom wall. First and second cord holes are formed in the bottom wall of the compartment. First and second movable seats are movably mounted in the compartment. The first movable seat includes a first pulley unit, and the second movable seat includes a second pulley unit. A folding/unfolding cord is wound around the first and second pulley units. The folding/unfolding cord has two end sections respectively extending through the first and second cord holes and are adapted to be extended through two sides of a shade and fixed to a bottom of the shade. An elastic cord-winding seat is mounted in the compartment. The first movable seat is located between the first elastic cord-winding seat and the second movable seat. The first elastic cord-winding seat includes a first elastic cord-winding spool and a second elastic cord-winding spool. A first actuation cord is wound around the first elastic cord-winding spool and has a distal end fixed to the first movable seat. A second actuation cord is wound around the second elastic cord-winding spool and has a distal end fixed to the second movable seat.
The double winding device according to the preferred teachings of the present invention uses two movable seats by replacing the fixed seat in the conventional designs with a movable seat, which is not a simple increase or reduction of the number of components. Specifically, by using two movable seats, the horizontal displacement can be achieved by shorter travel and in a shorter period of time. Another advantage of using two movable seats is that the folding/unfolding cord is provided with sufficient tension to reduce the possibility of entanglement, reliably positioning the shade in a horizontal state during folding/unfolding operation. A further advantage of using two movable seats is that the output force will not lessen too much even if the folding/unfolding cord are wound many rounds. This is because the output force acts on two points. Thus, the folding/unfolding cord can be wound more rounds such that a large-extent folding/unfolding of the shade can be achieved through short, horizontal displacement of the movable seats.
The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings.
The illustrative embodiments may best be described by reference to the accompanying drawings where:
All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiments will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.
DETAILED DESCRIPTION OF THE INVENTIONWith reference to
The double winding device further includes first and second movable seats 2 and 3 mounted in the compartment 10. The first movable seat 2 includes a first pulley unit 21. The second movable seat 3 includes a second pulley unit 31. A first folding/unfolding cord 23 is wound around the first and second pulley units 21 and 31. Two end sections 23A and 23B of the first folding/unfolding cord 23 are respectively extended through the cord holes 11 and 12 and can be extended through two sides of a shade 5 and fixed to two points P1 of a bottom of the shade 5.
The first movable seat 2 and the second movable seat 3 are substantially identical. The first movable seat 2 includes a body 20 receiving the first pulley unit 21. The head rail 1 includes two opposite vertical walls 16, and a ledge 15 is formed on each vertical wall 16 (
The first pulley unit 21 and the second pulley unit 31 are substantially identical. With reference to
A first elastic cord-winding seat 4 is mounted in the compartment 10 and adjacent to one of the first and second movable seats 2 and 3. In the embodiment shown in
With reference to
With reference to
Thus, the horizontal displacement of the first folding/unfolding cord 23 can be achieved by shorter travel and in a shorter period of time. Furthermore, the spacing between the first and second movable seats 2 and 3 permits sufficient tension imparted to the first folding/unfolding cord 23, reducing the possibility of entanglement of the first folding/unfolding cord 23 and reliably positioning the shade 5 in a horizontal state during folding/unfolding operation.
Furthermore, the moving distance between the first and second movable seats 2 and 3 is shortened. The output force will not lessen too much even if the folding/unfolding cord 23 is wound many rounds. This is because the output force acts on two points. Thus, the retrieving cords can be wound more rounds such that a large-extent folding/unfolding of the shade 5 can be achieved through short, horizontal displacement of the movable seats 2 and 3.
In another embodiment shown in
With reference to
Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
Claims
1. A double winding device for a window shade without a pull cord, with the double winding device comprising:
- a head rail including a compartment having a bottom wall, with first and second cord holes formed in the bottom wall of the compartment;
- first and second movable seats movably mounted in the compartment, with the first movable seat including a first pulley unit, with the second movable seat including a second pulley unit, with a folding/unfolding cord wound around the first and second pulley units, with the folding/unfolding cord having two end sections respectively extending through the first and second cord holes and adapted to be extended through two sides of a shade and fixed to a bottom of the shade; and
- first and second elastic cord-winding seats mounted in the compartment, with the first movable seat located between the first elastic cord-winding seat and the second movable seat, with the second movable seat located between the second elastic cord-winding seat and the first movable seat, with the first and second elastic cord-winding seats respectively including a first elastic cord-winding spool and a second elastic cord-winding spool, with a first actuation cord wound around the first elastic cord-winding spool and having a distal end fixed to the first movable seat, with a second actuation cord wound around the second elastic cord-winding spool and having a distal end fixed to the second movable seat.
2. The double winding device as claimed in claim 1, with the first pulley unit including at least one roller.
3. The double winding device as claimed in claim 2, with said at least one roller of the first pulley unit including three rollers.
4. The double winding device as claimed in claim 3, with the first pulley unit further including an axle extending through the three rollers, with the three rollers being independently rotatable about the axle.
5. The double winding device as claimed in claim 1, with the first movable seat including a body, with the body receiving the first pulley unit, with the head rail including two opposite vertical walls, with a ledge formed on each of the two vertical walls, with at least one first wheel rotatably mounted to each of two lateral sides of the body and rollable along one of the ledges of the head rail, with at least one second wheel rotatably mounted to each of the two lateral sides of the body and rollable along one of the two vertical walls.
6. A double winding device for a window shade without a pull cord, with the double winding device comprising:
- a head rail including a compartment having a bottom wall, with first and second cord holes formed in the bottom wall of the compartment;
- first and second movable seats movably mounted in the compartment, with the first movable seat including a first pulley unit, with the second movable seat including a second pulley unit, with a folding/unfolding cord wound around the first and second pulley units, with the folding/unfolding cord having two end sections respectively extending through the first and second cord holes and adapted to be extended through two sides of a shade and fixed to a bottom of the shade; and
- an elastic cord-winding seat mounted in the compartment, with the first movable seat located between the first elastic cord-winding seat and the second movable seat, with the first elastic cord-winding seat including a first elastic cord-winding spool and a second elastic cord-winding spool, with a first actuation cord wound around the first elastic cord-winding spool and having a distal end fixed to the first movable seat, with a second actuation cord wound around the second elastic cord-winding spool and having a distal end fixed to the second movable seat.
7. The double winding device as claimed in claim 6, with the first pulley unit including at least one roller.
8. The double winding device as claimed in claim 7, with said at least one roller of the first pulley unit including three rollers.
9. The double winding device as claimed in claim 8, with the first pulley unit further including an axle extending through the three rollers, with the three rollers being r independently rotatable about the axle.
10. The double winding device as claimed in claim 6, with the first movable seat including a body, with the body receiving the first pulley unit, with the head rail including two opposite vertical walls, with a ledge formed on each of the two vertical walls, with at least one first wheel rotatably mounted to each of two lateral sides of the body and rollable along one of the ledges of the head rail, with at least one second wheel rotatably mounted to each of the two lateral sides of the body and rollable along one of the two vertical walls.
Type: Application
Filed: Jun 21, 2011
Publication Date: Dec 29, 2011
Inventors: HANS HONG (CHANGHUA COUNTY), WEI SHUN HONG (CHANGHUA COUNTY)
Application Number: 13/164,881
International Classification: A47H 5/02 (20060101);