1 BLIND CORD WINDER INTEGRATING WITH STOPPING 2 CONTROL 3 FIELD OF THE INVENTION 4 The present invention relates to a control unit for an open/ close device built-in or 5 movably installed at window openings of a building and more specifically to a blind cord 6 winder integrating with stopping control. 7 BACKGROUND OF THE INVENTION 8 Blinds of early days were controlled by blind cords where a switching controller was 9 installed at one end of the track located on top of a blind. A bead chain or a blind cord 10 was hanging down from the switching controller to lift or lower the blind by pulling the 11 bead chain. However, accidents of strangling small children by the bead chains have 12 been occurred, therefore, blinds with bead chains have been forbidden in many countries. 13 Hence, cordless blinds become household necessities. Even though there are many 14 different designs of cordless blinds, their switching operation is not as convenient as 15 blinds with cords. 16 The conventional cordless blinds hide the blind cords inside the blind with an 17 exposed spool to collect the blind cords and are operated by an extra installed stopping 18 control device to fully open/ close the cordless blinds. However, the cordless blinds can 19 not be stopped at any position according to user needs. Furthermore, the stopping 20 control device of a cordless blind is customized and is designed and manufactured 21 according to the weight and dimension of a cordless blind. If a stopping control device 22 does not match with the dimension and weight of a cordless blind, the cordless blind 23 either suddenly drops to hurt someone below or completely and automatically lifts 24 without fully close function. Moreover, the exposed spool is easily contaminated when 25 used in years where the blind cords can not easily be rolled up. It is also 26 time-consuming to install cordless blinds with exposed spools. 27 SUMMARY OF THE INVENTION The main purpose of the present invention is to provide a blind cord winder 1 1 integrating with stopping control to minimize the blind stopping component for easy 2 component integration and installation and to enable users to stop the cordless blind at 3 any position during lifting or lowering the cordless blind. 4 Another purpose of the present invention is to provide a blind cord winder 5 integrating with stopping control to avoid exposure of blind cords from contamination, to 6 avoid sudden dropping of the cordless blind to hurt someone below, and to further reduce 7 lifting force to open a cordless blind. 8 According to the present invention, a blind cord winder integrating with stopping 9 control is disclosed where an envelope of the blind cord winder consists of a first 10 compartment and a second compartment jointed together. The blind winder comprises a 11 spool, a force-feedback mechanism, and a braking cushion mechanism. The spool is 12 installed inside the first compartment where one side of the first compartment has a shaft 13 cavity. The force-feedback mechanism is installed inside the shaft cavity and the 14 force-feedback mechanism includes a shaft sleeve and a volute spring. One end of the 15 volute spring is connected to the shaft sleeve and the other end of the volute spring is 16 fastened at the first compartment to provide a reposition elastic force for the shaft sleeve 17 to return to the original position. The braking cushion mechanism is installed inside the 18 second compartment and includes a friction ring, a friction spring, and a trigger sleeve 19 where the friction ring has a wear-proof annular inwall and is immovably installed inside 20 the second compartment. The friction spring is tightly plugged into the wear-proof 21 annular inwall with an extruded end for the trigger sleeve to trigger friction variation in a 22 single directional rotation of the trigger sleeve. Therefore, with the integration of the 23 braking cushion mechanism, the force-feedback mechanism, and the spool as one single 24 module, the cordless blind can easily be installed and can be stopped at any positions 25 according to user's needs. 26 DESCRIPTION OF THE DRAWINGS 27 FIG. 1 is a three-dimensional view of a blind cord winder integrating with stopping 2 1 control according to the preferred embodiment of the present invention. 2 HG. 2 is a three-dimensional component exploded view of the blind cord winder 3 according to the preferred embodiment of the present invention. 4 HG. 3 is a partially three-dimensional cross-sectional view of the blind cord winder 5 according to the preferred embodiment of the present invention. 6 HG. 4 is an axially cross-sectional view of the blind cord winder according to the 7 preferred embodiment of the present invention. 8 HG. 5 is a three-dimensional view illustrating the blind cord winder installed in a 9 cordless blind according to the preferred embodiment of the present invention. 10 HG. 6 is a radically side view illustrating the blind cord winder installed in a 11 cordless blind according to the preferred embodiment of the present invention. 12 HG. 7A to HG. 7C are the cross-sectional views illustrating the rotations of the 13 braking cushion mechanism of the blind cord winder during lifting, when stop, and 14 during lowering the cordless blind according to the preferred embodiment of the present 15 invention. 16 DETAILED DESCRIPTION OF THE INVENTION 17 With reference to the attached drawings, the present invention is described by means 18 of the embodiment(s) below where the attached drawings are simplified for illustration 19 purposes only to illustrate the structures or methods of the present invention by 20 describing the relationships between the components and assembly in the present 21 invention. Therefore, the components shown in the figures are not expressed with the 22 actual numbers, actual shapes, actual dimensions, nor with the actual ratio. Some of the 23 dimensions or dimension ratios have been enlarged or simplified to provide a better 24 illustration. The actual numbers, actual shapes, or actual dimension ratios can be 25 selectively designed and disposed and the detail component layouts may be more 26 complicated. 27 According to the preferred embodiment of the present invention, a blind cord winder 3 1 100 integrating with stopping control is disclosed in FIG. 1 for a three-dimensional view, 2 FIG. 2 for a three-dimensional component exploded view, FIG. 3 for a partially 3 three-dimensional cross-sectional view, and FIG. 4 for an axially cross-sectional view. 4 The blind cord winder 100 has an envelope consisting of a first compartment 101 and a 5 second compartment 102 jointed together where the blind cord winder 100 comprises a 6 spool 110, a force-feedback mechanism 120, and a braking cushion mechanism 130. 7 The spool 110 is installed inside the first compartment 101 where the first 8 compartment 101 has a shaft cavity 103 at one side. The spool 110 can rotate as the 9 blind shaft 180 rotates to collect the blind cords 12 as shown in FIG. 5, for example the 10 spool 110 has a shaft jointing hole 112 located at an axis of the spool 110 so that the blind 11 shaft 180 can be penetrated through and rotated synchronously as shown in FIG. 4. 12 Moreover, a blind cord guiding hole 104 is formed on the bottom of the first 13 compartment 101 so that the blind cord 12 can be rolled up and released. The blind cord 14 winder 100 further comprises a cover 160 which is buckled at the other end of the first 15 compartment 101 corresponding to the shaft cavity 103 to keep the spool 110 inside the 16 first compartment 101. Furthermore, a confining disc 111 is jointed at the other end of 17 the spool 110 away from the blind cord guiding hole 104 to prevent the blind cord 112 18 from breaking away and keeping an effective rotation of the spool 110. 19 The force-feedback mechanism 120 is installed inside the shaft cavity 103 to provide 20 a reposition elastic force to roll up the blind. The force-feedback mechanism 120 at 21 least includes a shaft sleeve 121 and a volute spring 122 where one end of the volute 22 spring 122 is connected to the shaft sleeve 121 and the other end of the volute spring 122 23 is fastened in the shaft cavity 103 of the first compartment 101 such as the shaft of the 24 shaft sleeve 121 has a buckling part where the corresponding curved end of the volute 25 spring 122 is buckling to the buckling part. On the other hand, a buckling space is 26 reserved at one of the sides or the corners of the shaft cavity 103 of the first compartment 27 101 where the corresponding curved end of the volute spring 122 is buckling at the 4 1 buckling space. The reposition elastic force provided by the volute spring 122 is able to 2 rotate the shaft sleeve 121 to return to the original position. Preferably, the blind cord 3 winder 100 further comprises a partition 150 buckling to one side of the first 4 compartment 101 located between the first compartment 101 and the second 5 compartment 102 to confine the shaft sleeve 121 and the volute spring 122 inside the 6 shaft cavity 103. In the present embodiment, the partition 150 has a shaft hole with 7 meshed supporting bars connected to the shaft hole. 8 The braking cushion mechanism 130 is installed inside the second compartment 102. 9 The braking cushion mechanism 130 includes a friction ring 131, a friction spring 132, 10 and a trigger sleeve 140. The friction ring 131 has a wear-proof annular inwall 133 and 11 is immovably fastened inside the second compartment 102. At least an alignment 12 fillister 136 is formed on an outer annular surface of the friction ring 131 and a 13 corresponding alignment buckling strip is disposed in the second compartment 102 to 14 firmly fasten the friction ring 131 inside the second compartment 102 to prevent the 15 friction ring 131 from rotation. The friction spring 132 is tightly plugged into the 16 wear-proof annular inwall 133 and has an extruded end 134 for the trigger sleeve 140 to 17 trigger friction variation in a single directional rotation of the trigger sleeve 140 where 18 variable frictions at different rotation directions would be generated between the friction 19 spring 132 and the friction ring 131. The braking cushion mechanism 130 further 20 includes a ring plug 135 inserted in an opening end of the wear-proof annular inwall 133 21 to prevent breaking away of the friction spring 132 and to allow part of the trigger sleeve 22 140 to penetrate through. Preferably, the second compartment 102 is jointed to the 23 partition 150 to confine the trigger sleeve 140 inside the second compartment 102 24 without affecting the assembly of the force-feedback mechanism 120. 25 In the present embodiment, the shaft sleeve 121 has a first shaft jointing hole 123 26 and the trigger sleeve 140 has a second shaft jointing hole 141 where the first shaft 27 jointing hole 123 and the second shaft jointing hole 141 are aligned in the same axis. 5 1 The first shaft jointing hole 123 and the second shaft jointing hole 141 are non-circular 2 holes such as a hexagon or a jointing hole with a single or a plurality of axial confining 3 bars or a triangle, a tetragon, or non-circular trimmed annular holes. Therefore, the 4 shaft sleeve 121 and the trigger sleeve 140 are able to individually assemble without 5 connections and can rotate synchronously. The blind cord winder 100 further 6 comprises a blind shaft 180 penetrating through the first shaft jointing hole 123 of 7 the shaft sleeve 121 and the second shaft jointing hole 141 of the trigger sleeve 8 141 and even penetrating through the third shaft jointing hole 112 of the spool 110. 9 As shown in FIG. 5, the clockwise and anticlockwise rotations of the blind shaft 10 180 enable synchronously rolling up and releasing the blind cord 12 and further 11 enable opening/ closing the blind 10. Since the blind cord winder 100 is in fully 12 penetrating status where the blind shaft 180 penetrates through the first 13 compartment 101, the shaft cavity 103, and the second compartment 102. In a 14 various embodiment, a driving motor 190 is disposed and connected to one end of 15 the blind shaft 180 to achieve effort-saving to open/ close the blind 10. 16 Therefore, the spool 110, the force-feedback mechanism 120, and the braking 17 cushion mechanism 130 can be integrated in one module. As shown in FIG. 5 18 and FIG. 6, the blind cord winder 100 can be easily assembled in the blind 10 19 where the blind cord winder 100 can be fastened at the blind fixing bar 11 through 20 buckling or screwing without extra installation procedure as installing the exposed 21 spool of a conventional cordless blind. The blind cord 12 can be gradually rolled 22 up by the spool 110 as the rotation of the blind shaft 180 and then the blind cord 23 12 is stored in the first compartment 101 where the blind 10 is in open status. 24 When the blind cord 12 is gradually released by the spool 110 through the blind 25 cord guiding hole 104, the blind 10 is in close status. Through the blind cord 26 winder 100, the cordless blind 10 can be stopped at any positions during lifting or 27 lowering the cordless blind 10 and the blind cord 12 is sealed up to prevent 6 1 contamination. 2 In the afore described blind cord winder 100, the trigger sleeve 140 is 3 composed of a first separating part 171 and a second separating part 172 where the 4 first separating part 171 has a trigger part 142 and the second separating part 172 5 has a stopping part 143. The second shaft jointing hole 141 of the trigger sleeve 6 140 can be disposed at the first separating part 171 or/and at the second separating 7 part 172 depending on different needs. The extruded end 134 of the friction 8 spring 132 is located in a gap 144 between the trigger part 142 and the stopping 9 part 143 as shown in FIG. 7A to FIG. 7C. The trigger part 142 and the stopping 10 part 143 are assembled with the friction spring 132 in a specific way so that the 11 friction between the friction spring 132 and the friction ring 131 is reduced when 12 the trigger part 142 contacts with the extruded end 134. In the present 13 embodiment, the stopping part 143 and the trigger part 142 can be two 14 corresponding side walls of two separated extruded arcs. To be more specific, 15 the extruded end 134 of the friction spring 132 is extruded toward the axis of the 16 friction spring 132, and the trigger part 142 and the stopping part 143 are plugged 17 into the friction spring 132. 18 In a various embodiment, the trigger sleeve 140 can be formed in one body 19 having a trigger part 142 and a stopping part 143 where the extruded end 134 is 20 located in a gap 144 between the trigger part 142 and the stopping part 143. The 21 trigger part 142 and the stopping part 143 are assembled with the friction spring 22 132 in a specific way so that the friction between the friction spring 132 and the 23 friction ring 131 is reduced when the trigger part 142 contacts with the extruded 24 end 134. 25 The blind cord winder 100 can lift and open the blind 10 due to the action of 26 force-feedback mechanism 120. As shown in FIG. 7A, when the extruded end 27 134 contacts with the counterclockwise spiral part of the friction spring 132, the 7 1 trigger part 142 is located at the clockwise side of the extruded end 134 and the 2 stopping part 143 is located at the counterclockwise side of the extruded end 134. 3 When the trigger part 142 contacts with the extruded end 134, the friction spring 4 132 is stretched which would slightly increase the number of coils, i.e., the 5 diameter of the friction spring 132 would slightly be decreased to reduce the 6 friction between the friction spring 132 and the friction ring 131 as the reduced 7 friction F1 shown in FIG. 7A where the required counterclockwise rotation force 8 of the trigger part 142 can be reduced. On the contrary, when the stopping part 9 143 contacts with the extruded end 134, the friction spring 132 is pushed to 10 increase its diameter, however, the friction ring 131 confines the maximum 11 diameter of the friction spring 132 so that the friction between the friction spring 12 132 and the friction ring 131 would be the same or slightly larger as the preset 13 friction F2 shown in FIG 7B and FIG. 7C. Therefore, the clockwise rotation of the 14 stopping part 143 has to overcome the preset friction between the friction spring 15 132 and the friction ring 131, or the trigger sleeve 140 will not rotate. 16 As shown in FIG. 7A, when a user is exerted a lifting force P1 to the blind 10, once 17 the reposition elastic force S2 from the volute spring 122 is greater than the gravity S1 of 18 the cordless blind 10 minus the lifting force P1 from the user, i.e., S2 > (S1 - P1), the 19 trigger part 142 of the trigger sleeve 140 would contact with the extruded end 134 of the 20 friction spring 132 so that the number of coils of the friction spring 132 would slightly 21 increase where the diameter of the friction spring 132 relatively becomes smaller. Thus, 22 the friction between the friction spring 132 and the friction ring 131 obviously becomes 23 smaller where this reduced friction F1 is nearly zero as shown in FIG. 7A. By keeping 24 the friction ring 131 immovable, the trigger sleeve 140 and the friction spring 132 would 25 vertically counterclockwise rotate to drive the blind shaft 180 and the spool 110 to roll up 26 the blind cord 12 so that the cordless blind 10 can easily be lifted with minimum forces 27 where the final equation to lift the cordless blind 10 is S2 > (S1 - P1) + Fl. When the 8 1 lifting force P1 exerted by a user become smaller, the equation will become S2 (SI - P1) 2 + F1 where the cordless blind 10 is able to stop at any positions during lifting the cordless 3 blind 10. 4 As shown in FIG. 7B, when a user would like to stop the cordless blind 10 at any 5 position without any exerted forces, normally the gravity SI of the cordless blind 10 will 6 be slightly greater than the reposition elastic force S2 from the volute spring 122, i.e., SI 7 > S2, to make the trigger sleeve 140 to vertically clockwise rotate, however, the stopping 8 part 143 of the trigger sleeve 140 will contact with the extruded end 134 of the friction 9 spring 132 so that the number of coils of the friction spring 132 is the same or the friction 10 spring 132 expands and becomes larger. Thus, the friction between the friction spring 11 132 and the friction ring 131 can be maintained at the preset value as the original friction 12 F2 shown in FIG 7B where F2 > Fl. When the cordless blind 10 has a different 13 specification to make the gravity Si of the cordless blind 10 be even larger, the original 14 friction F2 can be increased due to the expansion of the friction spring 132 by contacting 15 the stopping part 143 where the equation is Si S2 + F2. Therefore, when the friction 16 ring 131 and the friction spring 132 are not moving, the trigger sleeve 140 would not 17 move, either, so that the cordless blind 10 is able to stop at any position. 18 Furthermore, as shown in FIG. 7C, when a user would like to lower the cordless 19 blind 10 and exert a lowering force P2 to the cordless blind 10 where P2 is in the same 20 direction as the gravity Si of the cordless blind 10, moreover, the blind shaft 180, the 21 spool 110, the shaft sleeve 121, and the trigger sleeve 140 are linking together. The 22 vertically counterclockwise rotation of the shaft sleeve 121 and the trigger sleeve 140 is 23 caused by the reposition elastic force S2 from the volute spring 122. Once the total 24 forces of the gravity S1 of the cordless blind 10 plus the lowering force P2 from the user 25 is greater than the total forces of the reposition elastic force S2 plus the original friction 26 F2, i.e., (S1 + P2) > (S2 + F2), thus, the stopping part 143 of the trigger sleeve 140 would 27 contact with the extruded end 134 of the friction spring 132 where the trigger sleeve 140 9 1 and the friction spring 132 still can vertically clockwise rotate to lower and close the 2 cordless blind 10. When the lowering force P2 from a user becomes smaller until (Si + 3 P2) (S2 + F2), the cordless blind 10 is able to stop at any position during lowering. 4 The above description of embodiments of this invention is intended to be illustrative 5 but not limited. Other embodiments of this invention will be obvious to those skilled in 6 the art in view of the above disclosure which still will be covered by and within the scope 7 of the present invention even with any modifications, equivalent variations, and 8 adaptations. 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 10