DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] Referring to FIGS. 1 ˜ 3 , a vertical retractable blind 10 is shown comprising a headrail 11 , a lifting rail 13 , a blind body 14 , a bottom rail 17 , and two positioning cords 15 a and 15 b.

[0024] The headrail 11 is fixedly transversely (horizontally) fastened to the top side of the window, having a first extension spring 12 a and a second extension spring 12 b bilaterally provided on the inside and horizontally aligned in line. The extension springs 12 a and 12 b each have an inner end respectively fixedly fastened to a part inside the headrail 11 . The other end of each of the extension springs 12 a and 12 b is defined as a connecting end.

[0025] The lifting rail 13 is a hollow transverse rod member arranged below the headrail 11 .

[0026] The blind body 14 is provided between the headrail 11 and the lifting rail 13 . As illustrated in FIG. 2 , the blind body 14 is a pleated sheet member (formed of a piece of coating-coated cloth or fabric and alternatively reversely folded into shape), forming a plurality of transverse pleats 141 .

[0027] The bottom rail 17 is fixedly transversely (horizontally) fastened to the bottom side of the window below the lifting rail 13 . Bracket means may be used to fixedly secure the bottom rail 17 to the bottom side of the window.

[0028] The positioning cords 15 a and 15 b are bilaterally symmetrically arranged in parallel between the headrail 11 and the bottom rail 17 and inserted through the lifting rail 13 . According to this embodiment, the positioning cords 15 a and 15 b each have a top end respectively connected to the connecting ends of the extension springs 12 a and 12 b in the headrail 11 and a bottom end respectively connected to the tension control members 16 a and 16 b at the bottom rail 17 . The tension control members 16 a and 16 b can be controlled to roll up the positioning cords 15 a and 15 b , so as to relatively adjust the tension of the positioning cords 15 a and 15 b . As indicated in FIG. 1 , one positioning cord, namely, the first positioning cord 15 a is extended horizontally leftwards in the headrail 11 from the connecting end of the first extension spring 12 a and then vertically turned downwards to the outside of the headrail 11 , and then vertically downwardly extended through the blind body 14 into the inside of the lifting rail 13 , and then extended horizontally rightwards in the lifting rail 13 toward the right end of the lifting rail 13 , and then vertically downwardly extended out of the lifting rail 13 toward the bottom rail 17 and then connected to the second tension control member 16 b . The other positioning cord, namely, the second positioning cord 15 b is extended horizontally rightwards in the headrail 11 from the connecting end of the second extension spring 12 b and then vertically turned downwards to the outside of the headrail 11 , and then vertically downwardly extended through the blind body 14 into the inside of the lifting rail 13 , and then extended horizontally leftwards in the lifting rail 13 toward the left end of the lifting rail 13 , and then vertically downwardly extended out of the lifting rail 13 toward the bottom rail 17 , and then connected to the first tension control member 16 a . Because the tension control members l 6 a and 16 b are obtained from conventional techniques and not within the scope of the claims of the present invention, no further detailed description in this regard is necessary.

[0029] The aforesaid statement describes the structure of the vertical retractable blind according to the first embodiment of the present invention. Normally, the tension force of the positioning cords 15 a and 15 b supports the lifting rail 13 at an elevation, and at the same time the user can hold the lifting rail 13 in horizontal and move it upwards or downwards. When the user released the hand from the lifting rail 13 , the lifting rail 13 is held at the adjusted elevation. When moving the lifting rail 13 upwards/downwards, the blind body 14 is relatively folded up/extended out.

[0030] Further, because the vertical retractable blind 10 keeps the cords 15 a and 15 b out of reach of children, it is safety in use.

[0031] According to the aforesaid embodiment, the first ends (the top ends) of the positioning cords 15 a and 15 b are respectively connected to the connecting ends of the extension springs 12 a and 12 b in the headrail 11 , so that the positioning cords 15 a and 15 b have a sufficient tension force to support the lifting rail 13 at a particular elevation and to let the lifting rail 1 b be movable between the headrail 11 and the bottom rail 17 by the user. Alternatively, the extension springs 12 a and 12 b can be respectively installed in the two ends of the headrail 11 . In this case, the outer end of each extension spring 12 a or 12 b is fixedly fastened to the headrail 11 , and the inner end of each extension spring 12 a and 12 b is connected to the corresponding positioning cord 15 a or 15 b . It is also applicable to fixedly secure the first ends (top ends) of the positioning cords 15 a and 15 b to the headrail 11 , and to connect the second ends (bottom ends) of the positioning cords 15 a and 15 b to a respective extension spring in the bottom rail 17 . The positioning cords 15 a and 15 b can be made of elastic cord members without existence of the extension springs. The extension springs can be eliminated even if the positioning cords have no elasticity. Further, the aforesaid tension control members 16 a and 16 b are not requisite members of the vertical retractable blind 10 , and can be eliminated.

[0032] In the aforesaid first embodiment of the present invention, the blind body 14 is constructed subject to the design of a pleated blind. Alternatively, the blind body 14 can be constructed subject to the design of a Honeycomb shade.

[0033] FIGS. 4 ˜ 7 show a vertical retractable blind 20 constructed according to the second preferred embodiment of the present invention. According to this embodiment, the vertical retractable blind 20 is comprised of a headrail 21 , a lifting rail 23 , a blind body 24 provided between the headrail 21 and the lifting rail 23 , and two positioning cords 25 a and 25 b adapted to hold the lifting rail 23 at the desired elevation. The major parts of this second embodiment are same as the equivalent parts of the aforesaid first embodiment. The main features of this embodiment are outlined hereinafter. As shown in FIG. 4 , the vertical retractable blind 20 further comprises two vertical guide rails 27 a and 27 b fixedly provided at two sides of the window. Each of the vertical guide rails 27 a and 27 b has a top end close to the headrail 21 and a bottom end slightly lower than the bottom side of the window. As shown in FIG. 6 , the vertical guide rails 27 a and 27 b each have a longitudinal guide groove 28 facing each other and adapted to receive the ends of the lifting rail 23 and to guide vertical movement of the lifting rail 23 along the vertical guide rails 27 a and 27 b (see FIG. 6 ).

[0034] The rear (bottom) ends of the positioning cords 25 a and 25 b are extended out of the lifting rail 23 into the longitudinal guide grooves 28 of the vertical guide rails 27 a and 27 b , and then extended vertically downwards along the longitudinal guide grooves 28 of the vertical guide rails 27 a and 27 b , and finally fixedly fastened to the bottom ends of the longitudinal guide grooves 28 of the vertical guide rails 27 a and 27 b.

[0035] During retractable or extending action of the blind body 24 , the lifting rail 23 is maintained horizontal between the vertical guide rails 27 a and 27 b (see FIGS. 5 and 6 ), therefore the blind body 24 does not fly in the wind and, can smoothly be folded up or extended out. In other words, the protruded portions of the positioning cords 25 a and 25 b outside the lifting rail 23 are maintained extended along the longitudinal grooves 28 of the vertical guide rails 27 a and 27 b (see FIG. 7 ), i.e., the protruded portions of the positioning cords 25 a and 25 b outside the lifting rail 23 are surrounded by the vertical guide rails 27 a and 27 b and protected out of reach of children or external bodies.

[0036] According to this embodiment, the first positioning cord 25 a is extended from the connecting end of the first extension spring 22 a leftwards in the headrail 21 for a certain distance and then extended vertically downwardly out of the headrail 21 , and then vertically extended through the blind body 24 (without affecting the retractable action of the blind body 24 ) into the inside of the lifting rail 23 , and then extended horizontally leftwards out of the left end of the lifting rail 23 into the longitudinal groove 28 of the first (left) vertical guide rail 27 a , and then extended longitudinally downwards along the longitudinal groove 28 of the first (left) vertical guide rail 27 a , and finally fixedly fastened to the bottom end of the of the longitudinal groove 28 of the first (left) vertical guide rail 27 a . The second positioning cord 25 b is extended from the connecting end of the second extension spring 22 b rightwards in the headrail 21 for a certain distance and then extended vertically downwardly out of the headrail 21 , and then vertically extended through the blind body 24 (without affecting the retractable action of the blind body 24 ) into the inside of the lifting rail 23 , and then extended horizontally rightwards out of the right end of the lifting rail 23 into the longitudinal groove 28 of the second (right) vertical guide rail 27 b , and then extended longitudinally downwards along the longitudinal groove 28 of the second (right) vertical guide rail 27 b , and finally fixedly fastened to the bottom end of the of the longitudinal groove 28 of the second (right) vertical guide rail 27 b.

[0037] FIGS. 8 ˜ 11 show a vertical retractable blind 30 constructed according to the third embodiment of the present invention. The vertical retractable blind 30 is comprised of a headrail 31 , a lifting rail 33 , a bottom rail 37 , a blind body 34 provided between the headrail 31 and the lifting rail 33 , and two positioning cords 35 a and 35 b adapted to hold the lifting rail 33 at the desired elevation. The major parts of this second embodiment are same as the equivalent parts of the aforesaid first embodiment. The main features of this embodiment are outlined hereinafter.

[0038] The vertical retractable blind 30 further comprises a supplementary blind body 39 connected between the lifting rail 33 and the bottom rail 37 . The supplementary blind body 39 can be constructed subject to the design of a Venetian blind, pleated blind, honeycomb shade, or the like. According to this embodiment, the supplementary blind body 39 is constructed subject to the design of a honeycomb shade (see FIG. 11 ).

[0039] As illustrated, the vertical retractable blind 30 comprises a first blind body 34 provided between the headrail 31 and the lifting rail 33 , and a second blind body 39 provided between the lifting rail 33 and the bottom rail 37 . The first blind body 34 and the second blind body 39 can be of different designs for different purposes (for example, the first blind body is a pleated blind and the second blind body is a honeycomb blind as shown in FIG. 11 ). Further, when lifting the lifting rail 33 to receive the first blind body 34 , the second blind body 39 is extended out as shown in FIG. 9 . On the contrary, when lowering the lifting rail 33 , the first blind body 34 is extended out, and the second blind body 39 is received. In short, the user can adjust the elevation of the lifting rail 33 to change the relative area ratio between the first blind body 34 and the second blind body 39 (when the lifting rail 33 lowered to the lower limit or upper limit position, the vertical retractable blind 30 works as a blind having a single blind body).

[0040] A blind made according to either of the aforesaid embodiments is safe in use because the positioning cords are kept out of reach of children. Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.