Patent Publication Number: US-11643871-B2

Title: Idler end for a roller blind

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of Canadian patent application No. 3077999, filed on Apr. 10, 2020, the contents of which is incorporated herein by reference in their entirety. 
     TECHNICAL FIELD 
     This invention relates generally to roller blinds, or window shades, and in particular to an idler end for such devices. 
     BACKGROUND 
     Conventional idler end for roller blind has a constant length, making it difficult to install, significantly increasing the labor required to install the roller blinds or window shades. In addition, the constant length of the idler end also may make it impossible to adjust the gaps between the ends of the roller blinds and end bracket, thus affecting the artistic value of the roller blinds or window shades. 
     Thus, there is a need to provide an adjustable idler end. 
     SUMMARY 
     An idler end with adjustable length is provided. In some embodiments, the idler end includes a housing, a shaft, a bias member, a pin, and a limiter. The external surface of the housing is configured to engage the roller tube. The housing includes a housing cavity. The shaft is at least partially disposed in the housing cavity. A second limiting counterpart is configured on the exterior surface of the shaft. The pin is disposed in the shaft and at least one end of the pin is exposed from the shaft. A bias member is configured to engage the housing and the shaft, biasing the housing and the shaft away from each other. A limiter is connected to the housing. A first limiting counterpart is configured on the limiter. The first limiting counterpart and the second limiting counterpart cooperate to limit the movement of the shaft relative to the housing to a maximum predetermined distance. This maximum predetermined distance is adjustable. In some embodiments, for example, the maximum predetermined distance can be adjusted by movement of the limiter, which causes a relative movement between the first and second limiting counterparts. In some embodiments, the movement of the limiter is rotation. 
     In some embodiments, one of the first and second limiting counterparts include at least two surfaces and the other one of the first and second limiting counterparts include at least one protrusion. The surfaces and the protrusion are configured to engage each other such that the movement of the shaft and the limiter is limited. The surfaces are disposed at different positions such that when the protrusion engages different surfaces the movement of one of the shaft and the limiter relative to the other is limited to different maximum predetermined distances. In some embodiments, the protrusion is in the form of a ridge. 
     In some embodiments, the limiter includes a stem, and the first limiting counterpart is configured on the stem. In some embodiments, the stem includes a groove on its exterior surface. One or more positioning protrusion and/or one or more screw connects the limiter to the housing. 
     In some embodiments, the external surface of the housing is configured for interference fit with the interior surface of a roller tube. In some embodiments, at least two opposing projections are disposed on the external surface of the housing for interference fit with the interior surface of the roller tube. 
     In some embodiments, the shaft includes a cavity and the bias member is disposed in the housing cavity and the shaft cavity. 
     In some embodiments, the pin and the shaft are formed in one piece. 
     In some embodiments, the shaft includes a second shaft cavity, and the pin is disposed therein. The shaft includes an aperture and at least a portion of the pin is exposed from the shaft. In some embodiments, the pin and the shaft are rotatable relative to each other. In some embodiments, a damping material is disposed between the pin and the shaft. In some embodiments, a lubricant and/or a bearing is disposed between the pin and the shaft. For example, the bearing may include ball bearings. 
     In some embodiments, the limiter comprises a through-bore and at least a part of the shaft is extendable through the through-bore. And in some embodiments, the pin is exposable from the limiter. 
     The idler end may be made of metal, plastic, wood, or a combination thereof. 
     In some embodiments, the shaft and the housing can rotate relative to each other. In some embodiments, they are configured to reduce the noise when rotated. For example, a damping material may be disposed between the shaft and the housing. In some embodiments, a lubricant and/or a bearing is disposed between the shaft and the housing. For example, the bearing may include ball bearings. 
     In some embodiments, the shaft includes a first positioning counterpart and the housing comprises a second positioning counterpart, which cooperate such that the shaft and the housing rotate together. One of the first positioning counterpart and the second positioning counterpart may include at least one projection and the other may be configured with corresponding receptacle. 
     In some embodiments, the housing includes a third limiting counterpart that cooperates with the second limiting counterpart such that the movement of the shaft toward the housing is limited to a minimum predetermined distance. In some embodiments, the third limiting includes a shoulder. 
     In some embodiments, the shaft comprises at least one tooth at a portion distal from the housing. 
     A roller blind comprising the idler end is also disclosed. 
     A method for installing a roller blind is also disclosed. The method includes disposing the idler end in a roller tube, limiting the movement of the shaft relative to the housing to a first range, installing the roller blind, and limiting the movement of the shaft relative to the housing to a second range, which is different from the first range. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference will now be made, by way of example, to the accompanying drawings which show example embodiments of the present application, and in which: 
         FIG.  1    is a side view of one embodiment of the idler end at a first predetermined length. 
         FIG.  2    is an exploded view of the idler end of  FIG.  1   . 
         FIG.  3    is a perspective exploded view of the idler end of  FIG.  1   . 
         FIG.  4    is a top view of one embodiment of the limiter. 
         FIG.  5    is a side view of the limiter of  FIG.  4   . 
         FIG.  6    is a side view of one embodiment of the shaft engaging the limiter of  FIG.  4   . 
         FIG.  7    is a sectional view of the idler end of  FIG.  1   . 
         FIG.  8    is a side view of one embodiment of the idler end at a second predetermined length. 
         FIG.  9    is a sectional view of the idler end of  FIG.  8   . 
         FIG.  10    is a sectional view with respect to the A-A line in  FIG.  9   . 
         FIG.  11    is a sectional view with respect to the B-B line in  FIG.  9   . 
         FIG.  12    is a sectional view with respect to the C-C line in  FIG.  9   . 
         FIG.  13    is a side view of the idler end of at a third predetermined length. 
         FIG.  14    is a side view of one embodiment of the idler end at a fourth predetermined length. 
         FIG.  15    is a sectional view of one embodiment of the idler end of  FIG.  14   . 
         FIG.  16    is a side view of a roller blind including an embodiment of the idler end of this disclosure. 
         FIG.  17    is a sectional view of the roller blind of  FIG.  12   . 
     
    
    
     DETAILED DESCRIPTION 
     In various examples, the present disclosure describes an idler end  10  including a limiting system for limiting movement between a shaft and a housing, and the movement can be limited to different predetermined ranges. Although the present disclosure provides examples, the disclosed methods and devices may be suitable for other purposes, with modification as appropriate. 
     Reference is now made to  FIGS.  1 ,  2 , and  3   . The idler end includes a limiter  1 , a pin  2 , a shaft  3 , a bias member  4 , positioning pins  5  and  6 , and a housing  7 . 
     For the ease of description, a longitudinal direction  100  is shown in  FIG.  1   . However, this does not necessarily mean that the dimension along this direction is larger than the dimensions in other directions. 
     The limiter  1  includes a flange  104 . In some embodiments, one or more projections  101  extend from the edge of the flange  104  to function as handles. In some embodiments, grooves are disposed on the outer edge of the projections  101  to facilitate engagement with the projections  101  to make it easier to move the projections  101 . In some embodiments, the flange  104  is disposed at the end  107  of the limiter  1 . In some embodiments, the limiter  1  does not include a flange  104  and the one or more projections  101  extend from the exterior surface of the through-bore  102 . 
     The limiter  1  includes a stem  105 . In some embodiments, a groove  103  is disposed around the exterior surface  108  of the stem  105 . In some embodiments, the groove  103  is circumferential around the stem  105 . In some embodiments, the groove  103  is around a portion of the circumference of the stem  105 . In some embodiments, the stem  105  is cylindrical. The stem  105  is hollow, and a through-bore  102  is formed in the stem  105  through the limiter  1 . In some embodiments, a first limiting counterpart  106  is disposed on the stem  105 . In some embodiments, the first limiting counterpart  106  includes more than one limiting portions. 
     The pin  2  includes a pin part  201 . In some embodiments, the pin part  201  is cylindrical. In some embodiments, the pin also comprises one or more enlarged portions  202 . In some embodiments, the enlarged portion  202  surrounds the pin part  201  circumferentially. In some embodiments, the enlarged portion  202  is disposed at various positions on the outer surface of the pin part  201 . In some embodiments, the enlarged portion  202  includes a damping material. 
     The shaft  3  comprises a shaft body  305 . The shaft  3  has an exterior surface  314 . A second limiting counterpart  306  is disposed on the external surface  314 . The first limiting counterpart  106  and the second limiting counterpart  306  are configured to cooperate with each other to limit the relative movement between the shaft  3  and the limiter  1 . In some embodiments, the first limiting counterpart  106  and the second limiting counterpart are configured to engage with each other. By change the portions of the first limiting counterpart  106  and/or the second limiting counterpart  306  that engage, the movement between the shaft  3  and the limiter  1  may be restricted to different extent. In some embodiments, the second limiting counterpart  306  is a protrusion. In some embodiments, the protrusion is in the form of a ridge extending along the length of the shaft body  305 . 
     In some embodiments, the shaft  3  includes an enlarged portion  303 . In some embodiments, the enlarged portion  303  is disposed at one end  313  of the shaft body  305 . In some embodiments, the shaft  3  also includes a shaft cap  307 . In some embodiments, the enlarged portion  303  is configured to reduce the vibration of the shaft  3  when the shaft  3  is rotated and/or to reduce the vibration of the idler end  10  when it rotates. In some embodiments, the enlarged portion  303  includes first positioning counterpart  312 . In some embodiments, the shaft cap  307  includes at least one tooth, such that the rotational force of the shaft  3  can be transferred to a counterpart device. In some embodiments, a force maybe applied to  307  such that the idler end  10  rotates. 
     The bias member  4  is configured to engage the housing  7  and the shaft  3  and exert a biasing force when compressed. In some embodiments, the bias member  4  is a spring, for example, a helical spring. In some embodiments, the bias member  4  comprises a resilient structure. In some embodiments, the bias member  4  comprises a resilient material, for example, an elastomer. In some embodiments, the bias member  4  has a first end  401  and a second end  402 . The first end  401  is configured to engage the shaft  3  and the second end  402  is configured to engage the housing  7 . In some embodiments, the bias member  4  is configured to engage the shaft  3  and the housing  7  at portions away from the ends. 
     The housing  7  includes an external surface  702 . In some embodiments, the external surface  702  is configured for interference fit with the interior surface of a roller tube. In some embodiments, at least two opposing projections  703  are configured on the external surface  702 , and the projections  703  are configured for interference fit with the interior surface of a roller tube. In some embodiments, the housing  7  includes a sidewall  705 . In some embodiments, the projections  703  extends along the longitudinal direction. In some embodiments, each projection  703  is in a form similar to a fin. 
     In some embodiments, the housing  7  further includes a flange  708 . 
     In some embodiments, the limiter  1  is connected to the housing  7  using positioning pins  5  and  6  extending inwardly from the housing  7 . A portion of each of the positioning pins  5  and  6  are disposed in the groove  103  such that the movement of the limiter  1  is longitudinally restricted relative to the housing  7 , while as the same time at least one of the limiter  1  and the housing  7  can rotate relative to the other. In some embodiments, one positioning pin  5  is used. In some embodiments, 3, 4, 5, 6, 7, 8, 9, or more positioning pins are used. In some embodiments, the positioning pin  5  or  6 , independently, may be in the form of screws. In some embodiments, some of the positioning pins are in the form of screws while some other positioning pins are in the form of retractable pins. In some embodiments, when the housing  7  and the limiter  1  are connected, the flange  104  is disposed adjacent to or in contact with the flange  708 . In some embodiments, at least one of the screws is driven through the sidewall  705  of the housing  7   
     Each of the limiter  1 , pin  2 , shaft  3 , bias member  4 , positioning pins  5 ,  6 , and the housing  7  may be made of metal, plastic, rubber, wood, or other suitable material, or a combination thereof. 
     Reference is now made to  FIGS.  4  to  6   . The first limiting counterpart  106  includes four surfaces  1061 ,  1062 ,  1063 , and  1064  configured to engage the second limiting counterpart  306 .  FIG.  5    shows that the four surfaces  1061 ,  1062 ,  1063 , and  1064  are disposed at different distances from the end  107  of the limiter  1 . When one of the surfaces  1061 ,  1062 ,  1063 , and  1064  engages the second limiting counterpart  306 , the movement of the shaft  3  with respect to the limiter  1  is limited to different maximum distances. In some embodiments, protrusions, for example blocking protrusions  1065  and  1066 , are disposed adjacent to the surfaces  1062  and  1063 , respectively. In some embodiments, the protrusions help to hinder unintentional disengagement between the first limiting counterpart  106  and the second limiting counterpart  306 . In some embodiments, the first limiting counterpart  106  and the second limiting counterpart  306  may be configured for frictional contact therebetween such that the unintentional disengagement therebetween is hindered. 
     In some embodiments, the first limiting counterpart  106  includes one or more protrusions, and the second limiting counterpart  306  includes more than one surfaces configured to engage the one or more protrusions of the first limiting counterpart  106  such that the first limiting counterpart  106  and the second limiting counterpart  306  can cooperate to limit the movement of the shaft  3  relative to the limiter  1 . 
     In some embodiments, the first limiting counterpart  106  includes more or fewer than four surfaces for engaging the limiting counterpart  306  and the protrusions may be disposed next to one or more of the surfaces, such that movement of the shaft  3  relative to the limiter  1  can be limited to various numbers of different predetermined distances. In some embodiments, the first limiting counterpart  106  and/or the second limiting counterpart  306  are configured such that number of predetermined distances that the shaft  3  can move with respect to the housing  7  or the limiter  1  is infinite, i.e., the adjustment of the predetermined distances is stepless. 
     In some embodiments, a portion of the limiter  1  is moveable, for example, rotatable, such that a different portion of the first limiting counterpart  106  engages the second limiting counterpart  306 , such that the distance in which the shaft  3  can move relative to the limiter  1  is adjusted. As the first limiting counterpart  106  moves, for example, relative to the second limiting counterpart  306 , different surface of the first limiting counterpart  106  engages the second limiting counterpart  306 . For example,  FIG.  6    shows the surfaces  1061 ,  1062 ,  1063 , and  1064  engaging the second limiting counterpart  306 , and different lengths of the pin  2  and shaft  3  are exposed from the limiter  1 . 
     In some embodiments, the limiter  1  as a whole moves as a result of a movement of the limiter  1 , thus effecting the relative movement of the first limiting counterpart  106  and the second limiting counterpart  306  such that a different portion of the first limiting counterpart  106  engages the second limiting counterpart  306 , thus the distance that the shaft  3  can move toward the limiter  1  is adjusted. For example,  FIG.  6    shows the surfaces  1061 ,  1062 ,  1063 , and  1064  engaging the second limiting counterpart  306 , and different lengths of the pin  2  and the shaft  3  are exposed from the limiter  1 . In some embodiments, the movement of the limiter  1  may be rotation. In some embodiments, moving the limiter  1  is effected by exerting a force on the projections  101 . 
     In the embodiments where a protrusion is disposed adjacent to at least one of the surfaces  1061 ,  1062 ,  1063 , and  1064 , a stronger force is required to move the first limiting counterpart  106  such that a different surface of the first limiting counterpart  106  can engage the second limiting counterpart  306 . In some embodiments, the shaft  3  may be pushed away from the limiter  1 , thus the second limiting counterpart  306  disengages from the first limiting counterpart  106 , allowing at least one of the first limiting counterpart  106  and the second limiting counterpart  306  to move, for example, rotate, relative to the other such that a different portion of the first limiting counterpart  106  and the second limiting counterpart  306  can engage. 
     Reference is now made to  FIGS.  1 , and  7  to  15   . 
     The housing  7  has a housing cavity  701  and the shaft has a shaft cavity  301 . The bias member  4  is disposed in the housing cavity  701  and the shaft cavity  301 , exerting a force to bias the shaft  3  away from the housing, for example, with respect to the longitudinal direction  100 . 
     In some embodiments, the shaft  3  does not have a shaft cavity  301  and the bias member  4  engages the shaft  3  and the housing. For example, the bias member  4  may be received in the housing cavity  701  and one end of the bias member  4  engages one end of the shaft  3 . 
     In some embodiments, at least one of the shaft  3  and the housing  7  can rotate relative to the other. In some embodiments, for example, the portion of the outer surface  311  and the portion of the interior surface  710  of the housing that are adjacent to or in contact with each other may be complementarily shaped to facilitate the rotation relative to each other. For example, the portion of the outer surface  311  and the portion of the interior surface  710  of the housing that are adjacent to or in contact with each other may both be cylindrical, and have a common axis that is, for example, parallel to the longitudinal direction  100 . In some embodiments, a damping material  314  is disposed between the shaft  3  and the housing  7 , for example, to reduce the noise when at least one of the shaft  3  and the housing  7  rotates relative to the other. In some embodiments, a lubricant and/or bearing is disposed between the shaft  3  and the housing  7 . For example, the bearing may include ball bearings. 
     In some embodiments, the housing  7  and the shaft  3  cannot rotate relative to each other. In some embodiments, for example, the enlarged portion  303  includes a first positioning counterpart  312  and the housing  7  includes a second positioning counterpart  707 , which are complementarily designed. For example, the first positioning counterpart  312  may be in the form of one or more projections and the second positioning counterpart may be in the form of one or more corresponding receptacles. The projection may be in the form of a ridge and the receptacle may be in the form of a groove, as shown in  FIG.  10   . As such, when the first positioning counterpart  312  engages the second positioning counterpart  707 , the shaft  3  and the housing  7  cannot rotate relative to each other. In some embodiments, the second positioning counterpart  707  is in the form of one or more projections and the first positioning counterpart  312  may be in the form of one or more corresponding receptacles. When each of the positioning counterparts  312  and  707  comprises more than one ridges or grooves, respectively, there is inherent redundancy such that when one of the ridges or grooves fail, the system may still function as desired. In some embodiments, the first positioning counterpart  312  may also at least partially relieve the stress on the second limiting counterpart  306 . 
     In some embodiments, the housing  7  includes an engager  711  that engages one end of the bias member  4  such that the movement of the bias member  4  relative to the housing  7  is restricted at this end. In some embodiments, the engager  711  is in the form of a solid bottom  712 . In some embodiments, the engager  711  is in the form of a ridge or a series of protrusions. In some embodiments, the engager  711  is disposed at a position away from the bottom  712  of the housing  7 . In some embodiments, the shaft  3  includes an engager  302  in the cavity  301  such that the movement of the other end of the bias member  4  is restricted relative to the shaft  3 . In some embodiments, the engager  302  is disposed at an end of the cavity  301 . In some embodiments, the engager  302  is in the form of a shoulder. In some embodiments, the engager  302  is in the form of a continuous or discontinuous circumferential ridge. 
     In some embodiments, the maximum distance the shaft  3  can move toward the limiter  1  is such that the bias member  4  no longer exerts a force on the shaft  3  because the distance between the shoulder  312  and the engage  711  is larger than the length of the bias member  4 . 
     In some embodiments, the housing  7  includes a third limiting counterpart  706  as shown in  FIG.  7   , which is configured to engage the second limiting counterpart  306  such that the movement of the shaft  3  toward the housing  7  is limited, thus defining a minimum distance between a certain point of the shaft  3  and a certain point of the housing  7 , for example, between the enlarged portion  303  of the shaft  3  and the engager  711  of the housing  7 . In some embodiments, the third limiting counterpart is in the form of a shoulder or a protrusion. 
     In some embodiments, the shaft  3  can be pushed into the housing  7  such that the end  313  of the shaft  3  is adjacent to the bottom  712  of the housing  7  as shown in  FIG.  15   , defining a minimum distance between a certain point of the shaft and a certain point of the housing  7 . In some embodiments, for example, a third limiting counterpart  706  is not configured on the housing  7 . In some embodiments, the second positioning counterpart  707  may be configured to receive the second limiting counterpart  306 , thus allowing the shaft  3  to be pushed all the way into the housing cavity  701   
     The limiter  1  is connected to the housing  7  at or close to an end of the housing  7  distal from the housing bottom  712 . In some embodiments, the flange  104  of the limiter  1  is disposed adjacent to the flange  708  of the housing  7 . In some embodiments, positioning pins are used to attach the limiter  1  to the housing  7  by insertion into the groove  103  of the limiter  1  as discussed in this disclosure. 
     In some embodiments, at least a portion of the outer surface  311  of the shaft  3  is configured to be adjacent to or in contact with the interior surface of the through-bore  102  of the limiter  1 . In some embodiments, the shaft  3  extends through the through-bore  102  such that at least a portion of the shaft  3  is exposed from the limiter  1 . In some embodiments, the through-bore  102  and the outer surface  311  are complementarily shaped. For example, the through-bore  102  and the outer surface  311  may both be cylindrical. In some embodiments, at least one of the shaft  3  and the limiter  1  can rotate relative to the other around, for example, a common axis that is parallel to the longitudinal direction  100 . In some embodiments, the shaft  3  and the limiter  1  cannot rotate relative to each other. 
     The first limiting counterpart  106  engages the second limiting counterpart  306  such that the movement of the shaft  3  away from the housing  7  or toward the limiter  1  is limited to a predetermined maximum distance. By a movement of the first limiting counterpart  106  and the second limiting counterpart  306  relative to each other, the predetermined maximum distance can be adjusted because different portions of the first limiting counterpart  106  engages the second limiting counterpart  306 , or vice versa. For example, the movement of at least one of the first limiting counterpart  106  and the second limiting counterpart  306  relative to the other may be as discussed with respect to  FIGS.  4  to  6    in this disclosure. 
       FIG.  9    shows a sectional view of the idler end  10  at the length as shown as shown in  FIG.  8   . Here, a different portion of the first limiting counterpart  106  engages the second limiting counterpart  306  such that a shorter portion of the shaft  3  is exposed from the limiter  1  as compared to the configuration of the idler end  10  as shown in  FIGS.  1  and  7   . As shown in  FIG.  11   , the second limiting counterpart  306  engages a portion of the first limiting counterpart  106 . 
     In some embodiments, the pin  2  is received in a cavity  309  of the shaft  3 . In some embodiments, the enlarged portion  202  are received in recess  304  in the shaft. In some embodiments, the enlarged portion  202  fits snugly on the pin part  201 , thus the longitudinal movement of the pin part  201  relative to the shaft  3  is restricted. For example, the shaft  3  may be constructed in two halves. After the pin  2  is placed in one half, the other half is placed on the one half in a fashion similar to a clamshell. In some embodiments, the enlarged portion  303  and the shaft cap  307  are placed on the outer surface  311  of the shaft  3  such that the two halves of the shaft  3  are held together. The pin  2  extends through the aperture  310  such that at least a portion of the pin  2  is exposed from the shaft  3 . In some embodiments, the pin  2  is disposed in a mold for fabricating the shaft  3  before or after the material for forming the shaft  3  is disposed in the mold. When the shaft  3  is formed, the pin  2  is disposed in the shaft  3 . 
     In some embodiments, the pin  2  and the cavity  309  are shaped such that the pin  2  is rotatable relative to the shaft  3 . For example, the pin part  201  and the cavity  309  may be complementarily shaped, and the pin  2  and the shaft  3  can rotate relative to each other around a common axis. For example, they may both be cylindrical. In some embodiments, the common axis may be parallel to the longitudinal direction  100  of the idler end  10 . In some embodiments, the enlarged portion  202  comprises a damping material, which can, for example, reduce the noise when the pin  2  and the shaft  3  rotate relative to each other. In some embodiments, a lubricant and/or a bearing is disposed between the pin  2  and the shaft  3 . For example, the bearing may include ball bearings. 
     In some embodiments, the pin  2  and the shaft  3  cannot rotate relative to each other. For example, the pin  2  and the shaft  3  may be manufactured in one piece. For example, a portion of the pin  2  and a portion of the cavity  309  may be complementarily configured that that the rotational movement between the pin  2  and the shaft  3  are restricted as shown in  FIG.  12   . For examples, the pin  2  and the shaft  3  may be configured with complementary ridges and grooves. 
     In some embodiments, the cavity  301  and the cavity  309  are in mass communication through an aperture  308 . 
     In some embodiments, when the shaft  3  is pushed into the housing  3 , the pin  2  is not exposed from the limiter  1 , as shown in  FIG.  15   . In some embodiments, the pin  2  is not exposed from the limiter  1  because of the position of the shaft  3  as limited by the cooperation between the first limiting counterpart  106  and the second limiting counterpart  306 . For example, the second limiting counterpart  306  may be engaged to the surface  1064  of the first limiting counterpart  106  as shown in  FIG.  6   . 
       FIGS.  1 ,  8 ,  13 , and  14    show the different total maximum lengths of the idler end  1 , which is effected by the bias member  4  biasing the shaft to the predetermined maximum distance the shaft  3  is allowed to move away from the housing  7  effected by the cooperation between the first limiting counterpart  106  and the second limiting counterpart  306  when there is no force exerted on the shaft  3  opposite the force exerted by the bias member  4 . The total maximum lengths are thus adjustable by adjusting the predetermined maximum distance the shaft  3  can move relative to the housing  7 . For example, the different total maximum lengths of the idler end  10  may be the result of different engagements between the first limiting counterpart  106  and the second limiting counterpart  306  as shown in  FIG.  6   , where the second limiting counterpart  306  engages the different surfaces  1061 ,  1062 ,  1063 , and  1064  of the first limiting counterpart  106 , respectively. The predetermined maximum distances and the minimum distance define the predetermined distance ranges within which the shaft  3  can move. In some embodiments, a force may be exerted on the shaft  3  to counter the force exerted by the bias member  4  such that the shaft  3  moves within the predetermined distance range. In some embodiments, the movement of the shaft  3  within each predetermined distance range is stepless, resulting in infinite numbers of possible total lengths of the idler end  10  corresponding to each predetermined distance range. 
     Reference is now made to  FIGS.  16 - 17   .  FIG.  16    shows one embodiment of a roller blind  13  that includes the idler end  10  of this disclosure. The idler end  10  is installed at one end of the roller tube  9  and engages a bracket  12 . A blind  8  is installed on the roller tube  9 . Another idler end  11  is installed at the other end of the roller tube  9  and engages another bracket  12 . The idler end  11  may be the same or different from the idler end  10  of this disclosure. When the roller tube  9  rotates, the blind  8  is retracted or extended depending on the direction of the rotation of the roller tube  9  and the direction of installation of the blind  8  on the roller tube  9 . 
       FIG.  17    shows a sectional view of the idler end  10  installed in the roller tube  9 . The projection  703  engages the interior surface  907  of the roller tube  9  such that the housing  7  and the roller tube  9  rotate together. In some embodiments, the external surface  702  of the housing  7  engages the interior surface  901  of the roller tube  9 . 
     The pin  2  is received in the bracket  12 . In some embodiments, the pin  2  rotates relative to the bracket  12  such that the idler end  10  rotates. In some embodiments, the idler end  10  rotates by having the shaft  3  and the pin  2  rotate relative to each other. In some embodiments, the idler end  10  rotates by having the housing  7  and the shaft  3  rotate relative to each other. 
     In some embodiments, for example, the projections  101  include a handle to facilitate movement of the limiter  1 . In some embodiments, the handle is disposed in the gap between the bracket  12  and the limiter  1 . 
     A method for installing the roller bind  13  including the idler end  10  of this disclosure is also provided. The idler end  10  is installed in the roller tube  9 . The limiter  1  is moved to a position such that the shaft  3  retracts into the housing  7  such that the pin  2  is not exposed from the idler end  10 , for example, as shown in  FIG.  14   . The pin  2  can be retracted into the idler end  10  before or after the idler end  10  is installed in the roller tube  9 . The roller tube  9  is then positioned at a predetermined position. Then the limiter  1  is moved such that the pin  2  is exposed from the idler end  10 . Depending on the distance between the idler end  10  and bracket  12 , the limiter  1  is moved to different positions such that the first limiting counterpart  106  and the second limiting counterpart  306  move relative to each other, allowing the pin  2  to extend to an appropriate length such that pin  2  engages the bracket  12 . For example, the first limiting counterpart  106  and the second limiting counterpart  306  can move relative to each other such that the adjusted predetermined distance range corresponds to a range of length of the idler end  10  that includes the length required for the pin  2  to engage the bracket  12 . The bias member  4  then pushes the shaft  3 , and in turn, the pin  2  toward the bracket  12  until the pin  2  engages the bracket  12 , and the engagement between the pin  2  and the bracket  12  prevents further extension of the idler end  10 . 
     The preceding discussion provides many example embodiments. Although each embodiment represents a single combination of inventive elements, other examples may include all suitable combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, other remaining combinations of A, B, C, or D, may also be used. 
     The term “connected” or “coupled to” may include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). 
     Although the embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein. 
     Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.