Patent Publication Number: US-2022233011-A1

Title: Telescopic curtain guide rail

Description:
TECHNICAL FIELD 
     The disclosure relates to the technical field of curtain telescopic rods, and more particularly to a telescopic curtain guide rail. 
     BACKGROUND 
     Curtain is a household product installed at the window to play a role of shading. At present, various rooms have window walls with different widths. Therefore, the width of the window wall needs to be measured before the curtain guide rail is made, and then the corresponding curtain guide rail is made according to the measured width. This kind of curtain guide rail needs to be customized one by one, which cannot realize mass industrial production; it also needs on-site measurement, which wastes manpower and material resources; if there are errors in the measurement or manufacturing process, the curtain guide rail may not be used and needs to be reworked. Therefore, the traditional curtain guide rail adopts customization method, which has low efficiency, high cost and weak applicability. 
     Based on the above problems, more and more people begin to study the telescopic curtain guide rail, that is, the length of the curtain guide rail can be telescopically adjusted, and then one specification of the telescopic curtain guide rail can be applied to multiple sizes of windows. Since the telescopic curtain guide rail is still in its infancy, it needs to be wound with the help of multiple pulleys during the stretching and retracting of the curtain guide rail. The existing winding method leads to the increase of the volume of the curtain guide rail and the limited application occasions, which is not conducive to industrialized mass production. 
     SUMMARY 
     In view of the shortcomings of the related art, an objective of the disclosure is to provide a telescopic curtain guide rail. 
     In order to achieve the above objective, the disclosure adopts the following technical scheme: a telescopic curtain guide rail includes: an inner rail, an outer rail, a guide sleeve and a transmission unit, the inner rail is connected to a side of the outer rail, the inner rail is embedded in the outer rail and slidable along the outer rail, the transmission unit includes a driving wheel, a driven wheel, a first fixed pulley, a second fixed pulley and a conveyor belt (also referred to as belt); 
     the driving wheel and the driven wheel are respectively located at two opposite ends of the telescopic curtain guide rail, and the driving wheel is connected with a motor; the first fixed pulley is located at one of an inner end (also referred to as connecting end) of the inner rail and an inner end (also referred to as connecting end) of the outer rail, and the second fixed pulley is located at the other one of the inner end of the inner rail and the inner end of the outer rail, the driving wheel and the first fixed pulley are respectively disposed on two ends of the inner rail one of which is the inner end of the inner rail, or respectively disposed on two ends of the outer rail one of which is the inner end of the outer rail, the first fixed pulley and the second fixed pulley are located on same sides of the inner rail and the outer rail; the conveyor belt is wound on the driving wheel, the driven wheel, the second fixed pulley and the first fixed pulley sequentially in that order; 
     when the inner rail moves towards the outer rail, a distance between the driven wheel and the driving wheel is decreased while a distance between the first fixed pulley and the second fixed pulley is increased, or when the inner rail moves away from the outer rail, the distance between the driven wheel while the driving wheel is increased and the distance between the first fixed pulley and the second fixed pulley is decreased. 
     In an embodiment, the outer rail includes an upper-end first closed groove and a lower-end first opening groove, the inner rail includes an upper-end second closed groove and a lower-end second opening groove, the upper-end first closed groove is embedded in the upper-end second closed groove, the lower-end second opening groove is embedded in the lower-end first opening groove. 
     In an embodiment, a horizontal cross-sectional area of the lower-end second opening groove is less than that of the lower-end first opening groove, one side wall of the lower-end second opening groove is in contact with one side wall of the lower-end first opening groove, another side wall of the lower-end second opening groove and another side wall of the lower-end first opening groove together form a fixed pulley receiving chamber, a bottom of the fixed pulley receiving chamber includes a bottom surface of the outer rail and a bottom surface of the inner rail, and the bottom surface of the inner rail is located at an upper end of the bottom surface of the outer rail and coincides with the bottom surface of the outer rail; 
     the driving wheel is fixed at the end of the outer rail facing away from the inner rail, the driving wheel is connected to the motor, the first fixed pulley is fixed at the end of the outer rail close to the inner rail; the driven wheel is fixed at the end of the inner rail facing away from the outer rail, and the second fixed pulley is fixed at the end of the inner rail close to the outer rail. 
     In an embodiment, the inner rail further includes a first partition plate, the first partition plate is located in the lower-end second opening groove, and an upper end of the first partition plate is fixedly connected to an outer side of a bottom of the upper-end second closed groove, segments of the conveyor belt located on two sides of the driven wheel are respectively disposed on both sides of the first partition plate. 
     In an embodiment, the first fixed pulley is fixed at the outer rail through a first fixed part (first fixing member), the first fixed part covers outsides of the inner rail and the outer rail, the first fixed part covering the outside of the inner rail extends into the fixed pulley receiving chamber to fix a central axis of the first fixed pulley, and the first fixed part covering the outside of the outer rail is fixed at the outside of the outer rail through fixed screws. 
     In an embodiment, a central axis of the second fixed pulley is fixed on a side wall of the lower-end second opening groove close to the fixed pulley receiving chamber through a second fixed part (second fixing member), and the central axis of the second fixed pulley and the side wall of the lower-end second opening groove close to the fixed pulley receiving chamber are located in a same plane; and portions of the conveyor belt located on two sides of the second fixed pulley are respectively disposed on two sides of the side wall of the lower-end second opening groove close to the fixed pulley receiving chamber. 
     In an embodiment, the outer rail includes an L-shaped partition plate, the L-shaped partition plate is located in the fixed pulley receiving chamber and fixedly connected to an inner wall of the lower-end first opening groove, and portions of the conveyor belt located on two sides of the first fixed pulley are respectively located on two sides of the L-shaped partition plate. 
     In an embodiment, an opening of each of the lower-end first opening groove and the lower-end second opening groove includes right-angle bends, the right-angle bends of the lower-end first opening groove are matched with the right-angle bends of the lower-end second opening groove, and upper surfaces of the right-angle bends of the lower-end first opening groove and upper surfaces of the right-angle bends of the lower-end second opening groove are located at a same horizontal plane. 
     In an embodiment, the conveyor belt is connected with a conveyor belt buckle, a lower end of the conveyor belt buckle is connected with a rail trolley of curtain (also referred to as curtain slider), and the rail trolley of curtain is connected with a curtain cloth. 
     In an embodiment, groove bottoms of the upper-end first closed groove and the upper-end second closed groove are disposed with protrusions matched each other. 
     In an embodiment, the inner rail further includes a first partition plate, the first partition plate is located in the lower-end second opening groove, an upper end of the first partition plate is fixedly connected to an outer side of a bottom of the upper-end second closed groove, segments of the conveyor belt located on two sides of the driven wheel are respectively disposed on two sides of the first partition plate, and groove bottoms of the upper-end first closed groove and the upper-end second closed groove are disposed with protrusions matched each other; 
     one side wall of the lower-end second opening groove is in contact with one side wall of the lower-end first opening groove, another side wall of the lower-end second opening groove and another side wall of the lower-end first opening groove form a fixed pulley receiving chamber, a bottom of the fixed pulley receiving chamber includes a bottom surface of the outer rail and a bottom surface of the inner rail, and the bottom surface of the inner rail is located at an upper end of the bottom surface of the outer rail and coincides with the bottom surface of the outer rail; 
     the transmission unit further includes the first fixed pulley and the second fixed pulley; the driving wheel is connected with the motor; the first fixed pulley is located at one of an inner end of the inner rail and an inner end of the outer rail, and the second fixed pulley is located at the other one of the inner end of the inner rail and the inner end of the outer rail, the driving wheel and the first fixed pulley are respectively located at two ends of the inner rail including the inner end of the inner rail or respectively located two ends of the outer rail including the inner end of the outer rail, and the conveyor belt is wound on the driving wheel, the driven wheel, the second fixed pulley and the first fixed pulley; 
     the first fixed pulley is fixed at the outer rail through a first fixed part, the first fixed part covers outsides of the inner rail and the outer rail, the first fixed part covering the outside of the inner rail extends into the fixed pulley receiving chamber to fix a central axis of the first fixed pulley, and the first fixed part covering the outside of the outer rail is fixed at the outside of the outer rail through fixed screws. 
     In an embodiment, a central axis of the second fixed pulley is fixed on a side wall of the lower-end second opening groove close to the fixed pulley receiving chamber through a second fixed part, and the central axis of the second fixed pulley and the side wall of the lower-end second opening groove close to the fixed pulley receiving chamber are located in a same plane; and portions of the conveyor belt located on two sides of the second fixed pulley are respectively disposed on two sides of the side wall of the lower-end second opening groove close to the fixed pulley receiving chamber; and 
     the outer rail includes an L-shaped partition plate, the L-shaped partition plate is located in the fixed pulley receiving chamber and fixedly connected with an inner wall of the lower-end first opening groove, and portions of the conveyor belt located on two sides of the first fixed pulley are respectively located on two sides of the L-shaped partition plate. 
     In an embodiment, a rail trolley of curtain is fixed at a lower end of the conveyor belt, the rail trolley of curtain extends out from the outer rail and the inner rail, the rail trolley of curtain is movable along an axial direction of the outer rail and the inner rail driven by the conveyor belt, and the rail trolley of curtain includes a trolley body and a plurality of pulleys. 
     In an embodiment, the plurality of pulleys include a plurality of first pulleys and a plurality of second pulleys, the plurality of first pulleys and the plurality of second pulleys are rotatably connected to the trolley body, the trolley body includes an upper main body and a lower main body connected to the upper main body, both sides of the upper main body are provided with the plurality of first pulleys and the plurality of second pulleys, bottoms of the plurality of first pulleys form a first sliding surface, bottoms of the plurality of second pulleys form a second sliding surface, and the second sliding surface is higher than the first sliding surface. 
     In an embodiment, the inner rail is provided with a first sliding support surface, the outer rail is provided with a second sliding support surface, one of the first pulley and the second pulley is supported on the first sliding support surface when the rail trolley of curtain slides in the inner rail, or the other one of the first pulley and the second pulley is supported on the second sliding support surface when the rail trolley of curtain slides in the outer rail; and a height difference between the second sliding surface and the first sliding surface is matched with a height difference between the first sliding support surface and the second sliding support surface; 
     each of the plurality of first pulleys is arranged coaxially with corresponding one of the plurality of second pulleys, and a radius of the first pulley is greater than that of the corresponding second pulley; or, each of the plurality of first pulleys and corresponding one of the plurality of second pulleys have different rotation axes, the rotation axes of the first pulley and the corresponding second pulley are parallel and have a same height, and a radius of the first pulley is greater than that of the corresponding second pulley. 
     In an embodiment, each of the plurality of first pulleys is arranged coaxially with corresponding one of the plurality of second pulleys, or each of the plurality of first pulleys and corresponding one of the plurality of second pulleys have different rotation axes, the first pulley and the corresponding second pulley are arranged in a staggered manner in an axial direction of the first pulley and the second pulley, correspondingly, the first sliding support surface and the second sliding support surface are arranged in a staggered manner in the axial direction of the first pulley and the second pulley; 
     each of the plurality of first pulleys is arranged coaxially with the corresponding one of the plurality of second pulleys, the first pulley is close to the trolley body, the corresponding second pulley is located on a side of the first pulley facing away from the trolley body, and the first pulley is integrally formed with the corresponding second pulley. 
     In an embodiment, the rail trolley of curtain further includes a plurality of first guide wheels, the plurality of first guide wheels are rotatably connected to the upper main body, the plurality of first guide wheels transversely penetrates through the upper main body, wheel edges of the plurality of first guide wheels protrude outward relative to sides of the upper main body in a transverse direction, the plurality of first guide wheels are rotatable in the transverse direction, and the plurality of first guide wheels are higher than the second sliding surface; 
     the rail trolley of curtain further includes a plurality of second guide wheels, the plurality of second guide wheels are installed on a top of the upper main body and rotatable in the transverse direction, wheel edges of the plurality of second guide wheels protrude outward relative to the sides of the upper main body in the transverse direction, the plurality of second guide wheels are higher than the plurality of first guide wheels, and a radius of each of the plurality of second guide wheels is different from that of each of the plurality of first guide wheels; 
     the inner rail is provided with a first guide groove therein, the outer rail is provided with a second guide groove therein; when the rail trolley of curtain slides in the inner rail, one of the first guide wheel and the second guide wheel is located in the first guide groove and matched with the first guide groove, or when the rail trolley of curtain slides in the outer rail, the other one of the first guide wheel and the second guide wheel is located in the second guide groove and matched with the second guide groove; widths of the first guide groove and the second guide groove are different, and a width difference between the first guide groove and the second guide groove is matched with a diameter difference between the first guide wheel and the second guide wheel. 
     In an embodiment, the plurality of first pulleys have a same size and are symmetrically arranged on two sides of the trolley body, and the plurality of second pulleys have a same size and are symmetrically arranged on the two sides of the trolley body; the rail trolley of curtain further includes a plurality of outer pulleys arranged on the two sides of the trolley body in pairs, and the plurality of outer pulleys are located below the first sliding surface and is spaced a predetermined height from the first sliding surface. 
     In an embodiment, the trolley body is provided with threading through holes, and the conveyor belt includes a first conveyor belt and a second conveyor belt, the first conveyor belt is connected to the second conveyor belt and sleeved on the driving wheel and the driven wheel to make the driving wheel in transmission connection with the driven wheel, the second conveyor belt is engaged with the driving wheel or the driven wheel, and the first conveyor belt is a rope, the first conveyor belt passes through the threading through holes to make the rail trolley of curtain be connected to the first conveyor belt and move on the outer rail and/or the inner rail driven by the first conveyor belt. 
     In an embodiment, the trolley body includes an upper main body and a lower main body connected with the upper main body, the plurality of pulleys are rotatably installed on the upper main body; and the threading through holes include first threading through holes and second threading through holes, the upper main body is provided with the first threading through holes, the lower main body is provided with the second threading through holes, the first conveyor belt sequentially passes through the first threading through holes and the second threading through holes to fix the rail trolley of curtain, the upper main body of the rail trolley of curtain is slidable in the outer rail and/or the inner rail, the lower main body of the rail trolley of curtain is located outside the outer rail and the inner rail, and portions of the first conveyor belt are distributed on two sides of the trolley body of the rail trolley of curtain. 
     In an embodiment, the first conveyor belt includes a first rope section and a second rope section, the first rope section and the second rope section are separated from each other, and a first end of the first rope section is connected with a first end of the second conveyor belt, a second end of the first rope section passes through one of the first threading through holes and one of the second threading through holes and is fixed on the rail trolley of curtain, a first end of the second rope section is connected with a second end of the second conveyor belt, and a second end of the second rope section passes through the other one of the first threading through holes and the other one of the second threading through holes and is fixed on the rail trolley of curtain. 
     In an embodiment, the rail trolley of curtain further includes a threading fixed device, the threading fixed device is disposed on a side of the lower main body close to the second threading through holes or disposed in the second threading through holes, and the threading fixed device fixes the second end of the first rope section and the second end of the second rope section onto the rail trolley of curtain. 
     In an embodiment, each of the second threading through holes is a threading bolt hole arranged on the lower main body in a vertical direction, each of the second threading through holes includes a second through hole upper opening and a second through hole lower opening, the second through hole lower opening is disposed on a bottom of the lower main body; the threading fixed device includes threading bolts and threading nuts, the threading bolts are matched with the second threading through holes respectively, the threading nuts are matched with the second through hole upper openings of the second threading through holes; the second end of the first rope section and the second end of the second rope section are fixed on the rail trolley of curtain by cooperation of the threading bolts and threading nuts. 
     In an embodiment, the trolley body of the rail trolley of curtain is further provided with third threading through holes, the third threading through holes transversely penetrate through the trolley body of the rail trolley of curtain, and the first conveyor belt passes through the first threading through holes, the third threading through holes and the second threading through holes sequentially in that order. 
     In an embodiment, each of the first threading through holes includes a first end opening and a second end opening connected with the first end opening, the first end opening is disposed on one side of the upper main body, and the second end opening is disposed on the other side of the upper main body; the first end opening disposed on the one side surface of the upper main body is higher than ones of the plurality of pulleys disposed on the one side of the upper main body and outward protruding parts of the ones of the plurality of pulleys disposed on the one side of the upper main body, and the second end opening disposed on the other side of the upper main body is lower than the others of the plurality of pulleys disposed on the other side of the upper main body and outward protruding parts of the others of the plurality of pulleys disposed on the other side of the upper main body. 
     In an embodiment, each of the first threading through holes is an arc through hole transversely penetrating through the trolley body, and the first end opening and the second end opening are disposed on the two sides of the trolley body in a staggered manner. 
     In an embodiment, a connecting end (inner end) of the outer rail is inserted into the guide sleeve from a second end of the guide sleeve and matched with the guide sleeve, a free end (outer end) of the outer rail extends out from the guide sleeve, the inner rail is inserted into the guide sleeve from a first end of the guide sleeve and matched with the guide sleeve, a connecting end (inner end) of the inner rail is inserted into the outer rail, a free end (outer end) of the inner rail extends out from the guide sleeve, and a rail trolley of curtain is fixed at a lower end of the conveyor belt, and the rail trolley of curtain can pass through the guide sleeve when moves between the outer rail and the inner rail. 
     In an embodiment, a bottom surface of the guide sleeve is provided with a first support surface and a second support surface, the first support surface extends inward along an axial direction of the guide sleeve from the first end of the guide sleeve, the second support surface extends inward along the axial direction of the guide sleeve from the second end of the guide sleeve, the first support surface is connected with the second support surface, the first support surface is higher than the second support surface, and a step is formed at a connection between the first support surface and the second support surface, the first support surface supports the inner rail, the second support surface supports the outer rail, the outer rail abuts against the step, a height difference of bottom surfaces of the outer rail and the inner rail is matched to a height difference between the second support surface and the first support surface. 
     In an embodiment, the bottom surface of the guide sleeve is provided with a through groove penetrating the first support surface and the second support surface, a bottom of the inner rail is provided with a first sliding opening along the axial direction, a bottom of the outer rail is provided with a second sliding opening along the axial direction, the first sliding opening is communicated with the second sliding opening, and both ends of the through groove are respectively communicated with the first sliding opening and the second sliding opening; 
     the through groove includes a first through section and a second through section, the first through section is communicated/connected with the second through section, positions of the first through section and the second through section correspond to positions of the first support surface and the second support surface respectively, a width of the first through section close to the first end of the guide sleeve is greater than a width of the first sliding opening, a width of the first through section close to the second through section is matched with the width of the first sliding opening, and a width of the second through section is matched with a width of the second sliding opening; 
     the guide sleeve further includes transition tables, the transition tables are disposed on the both sides of the through groove and protrude upward relative to the first support surface, the transition tables are extended outward along the axial direction of the guide sleeve from the connection between the first support surface and the second support surface, an inner surface of the bottom of the outer rail is provided with a second sliding support surface, the second sliding support surface is axially extended from the connecting end of the outer rail towards the other end of the outer rail, the second sliding support surface is higher than the inner surface of the bottom of the outer rail; when the outer rail is matched with the guide sleeve, the transition tables are butted and matched with the second sliding support surface in the axial direction of the guide sleeve, and the second sliding support surface is higher than the transition tables; 
     the rail trolley of curtain extends out of the outer rail and the inner rail, the rail trolley of curtain is movable along the axial direction of the outer rail and the inner rail driven by the conveyor belt, the rail trolley of curtain is rotatably installed with a plurality of second pulleys, the plurality of second pulleys are slidable upward from the transition tables to the second sliding support surface or downward from the second sliding support surface to the transition tables. 
     In an embodiment, an upper part of the guide sleeve is provided with first guide rails and second guide rails, the first guide rails and the second guide rails are respectively disposed on the first support surface and the second support surface and extend along the axial direction of the guide sleeve, the first guide rails are connected to the second guide rails, connections of the first guide rails and the second guide rails are provided with second steps, the first guide rails are matched with a top of the inner rail to fix both sides of the inner rail relative to the guide sleeve, and the second guide rails are matched with a top of the outer rail to fix both sides of the outer rail relative to the guide sleeve. 
     In an embodiment, a thickness of the bottom surface of the guide sleeve gradually becomes thinner from the connection between the first support surface and the second support surface to the first end of the guide sleeve, an outer surface of the bottom of the guide sleeve is provided with a transition surface, the transition surface is disposed on a back of the first support surface and on the both sides of the through groove, one end of the transition surface close to the connection between the first support surface and the second support surface is matched with the outer rail, the other end of the transition surface is matched with the inner rail, and a height difference between the one end of the transition surface matched with the outer rail and the other end of the transition surface is matched with a height difference between the inner rail and the outer rail; 
     when the bottom surface of the guide sleeve is placed on a horizontal plane, the transition surface is arranged obliquely relative to the horizontal plane, and a height of the transition surface close to the connection between the first support surface and the second support surface is higher than a height of the transition surface close to the first end of the guide sleeve. 
     In an embodiment, the guide sleeve further includes a first mating surface and a second mating surface, the first mating surface extends inward along the axial direction of the guide sleeve from both side surfaces and a top surface of the first end of the guide sleeve together with the first support surface form an annular surface with an opening at a bottom thereof, the second mating surface extends inward along the axial direction of the guide sleeve from two side surfaces and a top surface of the second end of the guide sleeve and together with the second support surface form an annular surface with an opening at a bottom thereof; compared with the second mating surface, the first mating surface is closer to a central axis of the guide sleeve; in the axial direction of the guide sleeve, the first mating surface is connected with the second mating surface, and a third step is formed at a connection between the first mating surface and the second mating surface. 
     In an embodiment, the telescopic curtain guide rail further includes a fixed component, the fixed component passes through an outer housing of the guide sleeve from outside of the guide sleeve and partially extends into the guide sleeve, and the fixed component is connected with the inner rail and/or the outer rail to fix the inner rail and/or the outer rail relative to the guide sleeve; or, the fixed component includes a fixed bolt and a fixed plate, the fixed plate is disposed in the guide sleeve, the guide sleeve and the fixed plate are provided with fixed bolt holes matching with the fixed bolt, and the fixed plate moves inward to press and fix the inner rail, or moves outward to clamp and fix the inner rail between the fixed plate and the guide sleeve under rotating cooperation of the fixed bolt and the fixed bolt holes. 
     In an embodiment, the telescopic curtain guide rail further includes an adjusting component fixedly connected with the first fixed pulley and/or the second fixed pulley, the adjusting component is configured to cooperate with the first fixed pulley and/or the second fixed pulley to tension or loosen the conveyor belt, the guide sleeve is provided with an adjusting installation groove therein, and the adjusting installation groove is disposed in a space surrounded by the first support surface. 
     In an embodiment, the adjusting component includes an adjusting nut and an adjusting screw matched with the adjusting nut, and a cooperation of the adjusting screw and the adjusting nut drives the first fixed pulley and/or the second fixed pulley to move; the adjusting component further includes a stopper, upper and lower ends of the adjusting nut extend towards the stopper and are connected with the stopper, an installation area is formed between the stopper and the adjusting nut, the installation area is fixed with the first fixed pulley and/or the second fixed pulley, a side of the stopper close to the adjusting nut is an arc surface, portions of the conveyor belt located on two sides of the first fixed pulley and/or the second fixed pulley in the installation area are respectively located on two sides of the stopper; 
     one end of the adjusting installation groove is provided with an opening, the other end of the adjusting installation groove is provided with a baffle, the opening is disposed close to the second support surface, the adjusting component is fixed in the adjusting installation groove, the baffle is provided with a through hole, the adjusting screw passes through the through hole to match with the adjusting nut, and the adjusting screw drives the adjusting component to move away from or close to the baffle when being rotated; 
     a top wall of the adjusting installation groove is provided with a first opening, a bottom wall of the adjusting installation groove is provided with a second opening opposite to the first opening, the first fixed pulley and/or the second fixed pulley are fixed on the adjusting component through a fixed shaft, and two ends of the fixed shaft extend into the first opening and the second opening respectively; 
     the adjusting installation groove is disposed in the space surrounded by the first support surface, the adjusting component is fixed in the adjusting installation groove and slidably connected with the adjusting installation groove, the first fixed pulley is fixed on the adjusting component, and an end of a first outer rail inner wall abuts against the top wall of the adjusting installation groove, an end of a second outer rail inner wall of the outer rail abuts against the bottom wall of the adjusting installation groove, there is a third insertion gap between the bottom wall of the adjusting installation groove and the first support surface, and a bottom wall of a lower-end second opening groove of the inner rail passes through the third insertion gap and then is inserted into a second insertion gap. 
     In an embodiment, the outer rail includes an upper-end first closed groove and a lower-end first opening groove, a side wall of the lower-end first opening groove is provided with a first outer rail inner wall and a second outer rail inner wall extending inwardly towards the lower-end first opening groove, there is a first insertion gap between a bottom wall of the upper-end first closed groove and the first outer rail inner wall, there is a second insertion gap between a bottom wall of the lower-end first opening groove and the second outer rail inner wall, the conveyor belt is located between the first outer rail inner wall and the second outer rail inner wall; the inner rail includes an upper-end second closed groove and a lower-end second opening groove, a bottom wall of the upper-end second closed groove is inserted into the first insertion gap, and a bottom wall of the upper-end second opening groove is inserted into the second insertion gap. 
     In an embodiment, the outer rail includes the lower-end first opening groove, the inner rail includes the lower-end second opening groove, when the inner rail is engaged with the outer rail, a first side wall of the inner rail divides the lower-end first opening groove into a first cavity and a second cavity, the second fixed pulley is fixed on the inner rail through a second fixed component, the second fixed component is provided with a connecting clamp, the connecting clamp clamps an end of the first side wall, and portions of the conveyor belt located on two sides of the second fixed pulley are located in the first cavity and the second cavity respectively. 
     In an embodiment, the conveyor belt includes a first connecting section and a second connecting section connected each other, the first connecting section and the second connecting section are connected in a head-to-tail manner, the first connecting section is matched with the driving wheel, the second connecting section is wound on the first fixed pulley and the second fixed pulley, and a belt thickness of the first connecting section is greater than a belt thickness of the second connecting section; and 
     the first connecting section is one or more selected from the group consisting of a belt, a steel wire and a rope; and the second connecting section is one or more selected from the group consisting of a belt, a steel wire and a rope. 
     The beneficial effects of the disclosure are: the unique winding structure adopted by the disclosure ensures that the length of the conveyor belt remains unchanged and the conveyor belt is always in a tensioned state during the opening and closing of the curtain; the curtain guide rail of the disclosure is stretched and retracted to drive the positions of two fixed pulleys to change at the same time, the stretching and retracting operation is simple, the floor area is small, it is conducive to mass industrial production, has a wide range of application, and reduces the transportation cost and production cost. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic structural diagram of the telescopic guide rail according to an embodiment of the disclosure. 
         FIG. 2  is a schematic structural diagram of the winding of the conveyor belt according to an embodiment of the disclosure. 
         FIG. 3  is a schematic sectional diagram of the outer rail according to an embodiment of the disclosure. 
         FIG. 4  is a schematic sectional diagram of the inner rail according to an embodiment of the disclosure. 
         FIG. 5  is a schematic sectional diagram of the outer rail and the inner rail from a first view angle according to an embodiment of the disclosure. 
         FIG. 6  is a schematic sectional diagram of the outer rail and the inner rail from a second view angle according to an embodiment of the disclosure. 
         FIG. 7  is a schematic structural diagram of the curtain guide rail fixed device from a front view according to an embodiment of the disclosure. 
         FIG. 8  is a schematic structural diagram of the curtain guide rail fixed device from a bottom view according to an embodiment of the disclosure. 
         FIG. 9  is a schematic structural diagram of the curtain guide rail fixed device from a bottom view at a certain angle according to an embodiment of the disclosure. 
         FIG. 10  is a schematic structural diagram of the fixed component according to an embodiment of the disclosure. 
         FIG. 11  is a schematic structural diagram of the telescopic guide rail according to an embodiment of the disclosure. 
         FIG. 12  is a schematic sectional diagram of the portion A-A of the telescopic guide rail in  FIG. 11  according to an embodiment of the disclosure. 
         FIG. 13  is a partial schematic structural diagram of the cooperation of the inner rail, the outer rail and the curtain guide rail fixed device according to an embodiment of the disclosure. 
         FIG. 14  is a partial schematic structural diagram of the cooperation of the outer rail and the curtain guide rail fixed device according to an embodiment of the disclosure. 
         FIG. 15  is an internal schematic structural diagram of the telescopic guide rail according to an embodiment of the disclosure. 
         FIG. 16  is a schematic structural diagram of the rail trolley of curtain and the fixed component according to an embodiment of the disclosure. 
         FIG. 17  is a schematic structural diagram of the rail trolley of curtain from a top view according to an embodiment of the disclosure. 
         FIG. 18  is a schematic structural diagram of the rail trolley of curtain from a front view according to an embodiment of the disclosure. 
         FIG. 19  is a schematic structural diagram of the cooperation of the rail trolley of curtain, the inner rail and the outer rail according to an embodiment of the disclosure. 
         FIG. 20  is a schematic structural diagram of the cooperation of the rail trolley of curtain and the inner rail according to an embodiment of the disclosure. 
         FIG. 21  is a schematic structural diagram of the cooperation of the rail trolley of curtain and the outer rail according to an embodiment of the disclosure. 
         FIG. 22  is a schematic structural diagram of the rail trolley of curtain according to an embodiment of the disclosure. 
         FIG. 23  is a schematic structural diagram of the conveyor belt according to an embodiment of the disclosure. 
         FIG. 24  is a schematic structural diagram of the guide sleeve according to an embodiment of the disclosure. 
         FIG. 25  is a schematic structural diagram of the cooperation between the adjusting component and the adjusting installation groove according to an embodiment of the disclosure. 
         FIG. 26  is a schematic structural diagram of the cooperation between the adjusting component and the first fixed pulley according to an embodiment of the disclosure. 
         FIG. 27  is a schematic structural diagram of the cooperation of the inner rail, the outer rail and the guide sleeve according to an embodiment of the disclosure. 
         FIG. 28  is a schematic structural diagram of the outer rail according to an embodiment of the disclosure. 
         FIG. 29  is a schematic structural diagram of the cooperation between the outer rail and the inner rail according to an embodiment of the disclosure. 
         FIG. 30  is a schematic structural diagram of the cooperation of the inner rail, the outer rail and the guide sleeve according to an embodiment of the disclosure. 
         FIG. 31  is a schematic structural diagram of the cooperation of the second fixed pulley and the first side wall according to an embodiment of the disclosure. 
         FIG. 32  is a schematic sectional diagram of the cooperation between the adjusting component and the guide sleeve according to an embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF REFERENCE NUMERALS 
       1 —outer rail;  11 —L-shaped partition plate;  2 —inner rail;  21 —fixed pulley receiving chamber;  22 —first partition plate;  23 —bend;  31 —driving wheel;  32 —driven wheel;  33 —first fixed pulley;  331 —first fixed part;  34 —second fixed pulley;  35 —conveyor belt;  4 —rail trolley of curtain; 
       100 —curtain guide rail fixed device;  101 —guide sleeve;  102 —first support surface;  103 —second support surface;  104 —first guide rail;  105 —second guide rail;  106 —first mating surface;  107 —second mating surface;  108 —through groove;  109 —first through section;  110 —second through section;  111 —transition surface;  112 —transition table;  113 —fixed component;  114 —fixed bolt;  115 —fixed bolt hole;  116 —T-shaped nut;  117 —limit part;  201 —first sliding opening;  202 —first sliding support surface;  203 —first guide groove;  204 —second guide groove;  301 —second sliding opening;  302 —second sliding support surface;  401 —trolley body;  402 —first pulley;  403 —second pulley;  404 —first guide wheel;  405 —second guide wheel;  406 —outer pulley;  407 —first threading through hole;  408 —second threading through hole;  409 —third threading through hole;  410 —lead table;  411 —threading fixed device;  4111 —threading bolt;  4112 —threading nut;  4071 —first end opening;  4072 —second end opening;  4081 —second through hole upper opening;  4082 —second through hole lower opening;  501 —steel wire rope;  502 —synchronous belt;  503 —engaging portion; 
       1023 —step;  12 —upper-end first closed groove;  13 —lower-end first opening groove;  14 —first outer rail inner wall;  15 —second outer rail inner wall;  131 —first insertion gap;  132 —second insertion gap;  1011 —adjusting installation groove;  1012 —baffle;  1013 —through hole;  51 —stopper;  1014 —first opening;  1015 —second opening;  3331 —fixed shaft;  26 —first side wall;  27 —connecting clamp;  133 —third insertion gap;  311 —adjusting nut;  312 —adjusting screw;  351 —first connecting section;  352 —second connecting section. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In the following, the disclosure will be further described in combination with the accompanying drawings and specific embodiments: 
     As shown in  FIG. 1  to  FIG. 32 , an embodiment of the disclosure provides a telescopic curtain guide rail including: an inner rail  2 , an outer rail  1  and a transmission unit. The inner rail  2  is connected to a side of the outer rail  1 , the inner rail  2  is embedded in the outer rail  1  and slidable along the outer rail  1 . The transmission unit includes a driving wheel  31 , a driven wheel  32 , a first fixed pulley  33 , a second fixed pulley  34  and a conveyor belt  35 . The driving wheel  31  and the driven wheel  32  are respectively located at two opposite ends of the telescopic curtain guide rail, the two opposite ends of the telescopic curtain guide rail are the ends where the inner rail and the outer rail are away from each other, that is, the driving wheel and the driven wheel are located at two ends of the inner rail and the outer rail respectively. Specifically, the driving wheel can be located at one end of the inner rail or one end of the outer rail. The driving wheel  31  is connected to the motor. The first fixed pulley  33  and the second fixed pulley  34  are respectively located at the other ends of the inner rail and the outer rail, in order to distinguish the first fixed pulley from the second fixed pulley, the disclosure defines that the driving wheel and the first fixed pulley are located at two ends of the inner rail or the outer rail at the same time, and the driven wheel and the second fixed pulley are located at two ends of the outer rail or the inner rail at the same time. Of course, the first fixed pulley and the second fixed pulley are only to distinguish in naming, when the driving wheel and the second fixed pulley are located at two ends of the inner rail or the outer rail at the same time, it is only necessary to exchange the following first fixed pulley and the second fixed pulley of the disclosure. 
     The unique feature of the transmission unit of the disclosure is that the first fixed pulley  33  and the driving wheel  31  are fixed at both ends of the outer rail  1 , the second fixed pulley  34  and the driven wheel  32  are fixed at both ends of the inner rail  2 , and the winding mode of the conveyor belt  35  is the driving wheel  31 —the driven wheel  32 —the second fixed pulley  34 —the first fixed pulley  33 —the driving wheel  31 , and the first fixed pulley  33  and the second fixed pulley  34  are located on the same sides of the inner rail  2  and the outer rail  1 . This winding mode ensures that when the driving wheel  31  is close to the driven wheel  32 , the first fixed pulley  33  is away from the second fixed pulley  34 , and ensures that the total length of the conveyor belt  35  remains unchanged. The winding mode is simple, and the floor area is small, which reduces the production cost and transportation cost. 
     As shown in  FIG. 2  to  FIG. 6 , the outer rail  1  of the embodiment includes an upper-end first closed groove and a lower-end first opening groove, the inner rail  2  includes an upper-end second closed groove and a lower-end second opening groove, the upper-end first closed groove is embedded in the upper-end second closed groove, the lower-end second opening groove is embedded in the lower-end first opening groove. A horizontal cross-sectional area of the lower-end second opening groove is less than that of the lower-end first opening groove, one side wall of the lower-end second opening groove is in contact with one side wall of the lower-end first opening groove, the other side wall of the lower-end second opening groove and the other side wall of the lower-end first opening groove together form a fixed pulley receiving chamber  21 . In the above description, the closed groove (the upper-end first closed groove and the upper-end second closed groove) refers to that the groove has the bottom as shown at the upper ends of the inner rail  2  and the outer rail  1  in  FIG. 3  and  FIG. 4 , the opening groove (the upper-end first opening groove and the upper-end second opening groove) refers to that the groove is a cavity structure and the upper end surface of the cavity structure shares a surface with the bottom of the closed groove as shown at the lower ends of the inner rail  2  and the outer rail  1  in  FIG. 3  and  FIG. 4 . It can be clearly seen from the attached drawings that the lower end of the outer rail  1  is an integral opening groove structure, while the lower end of the inner rail  2  includes an opening groove structure and the fixed pulley receiving chamber  21 . Only the first fixed pulley is installed in the fixed pulley receiving chamber  21 , and the second fixed pulley is just located in the plane on the side shared by the lower-end second opening groove and the fixed pulley receiving chamber  21 . 
     As shown in  FIG. 2  to  FIG. 6 , a bottom of the fixed pulley receiving chamber  21  includes a bottom surface of the outer rail  1  and a bottom surface of the inner rail  2 , and the bottom surface of the inner rail  2  is located above the bottom surface of the outer rail  1  and coincides with the bottom surface of the outer rail  1 . The outer rail  1  includes an L-shaped partition plate  11 , the L-shaped partition plate  11  is located in the fixed pulley receiving chamber and fixedly connected with an inner wall of the lower-end first opening groove, and portions of the conveyor belt located on two sides of the first fixed pulley are respectively located on two sides of the L-shaped partition plate  11 . The inner rail  2  further includes a first partition plate  22 , the first partition plate  22  is located in the lower-end second opening groove, and an upper end of the first partition plate  22  is fixedly connected to an outside of a bottom of the upper-end second closed groove, segments of the conveyor belt located on both sides of the driven wheel are respectively disposed on both sides of the first partition plate  22 . 
     As shown in  FIG. 2  to  FIG. 6 , an opening of each of the lower-end first opening groove and the lower-end second opening groove includes bends  23 , the bends  23  of the lower-end first opening groove are matched with the bends  23  of the lower-end second opening groove, and upper surfaces of the bends of the lower-end first opening groove and upper surfaces of the bends of the lower-end second opening groove are located at a same horizontal plane. the bend  23  can be a right-angle bend or a bend with radian; the bend is set here because the rail trolley of curtain on the belt buckle needs to move between lower-end opening grooves of the inner rail  2  and the outer rail  1 , in order to ensure the smooth movement of the rail trolley of curtain, clamping plates are usually set inside and outside the lower-end opening grooves respectively, the bend here can ensure the smooth transition of the rail trolley of curtain from the inner rail  2  to the outer rail  1 , and smooth sliding in the overlapping area of the inner rail  2  and the outer rail  1 . The groove bottoms of the upper-end first closed groove and the upper-end second closed groove are disposed with protrusions matched each other. 
     As shown in  FIG. 6 , the first fixed pulley of the embodiment is fixed on the outer rail  1  through a first fixed part, the first fixed part covers outsides of the inner rail  2  and the outer rail  1 , the first fixed part covering the outside of the inner rail  2  extends into the fixed pulley receiving chamber  21  to fix a central axis of the first fixed pulley, and the first fixed part covering the outside of the outer rail  1  is fixed at the outside of the outer rail  1  through fixed screws. It is precisely because the first fixed pulley is fixed at the end of the contact between the outer rail  1  and the inner rail  2 , and the first fixed pulley is located in the fixed pulley receiving chamber  21  and needs to be fixed with the outer rail  1 , therefore, the application skillfully leads the first fixed pulley out of the fixed pulley receiving chamber  21  and fixed at the upper end of the outer rail  1  with the help of a special first fixed part structure. Specifically, as described in  FIG. 6 , the first fixed part  331  covers the outer side of the outer rail  1  and the inner rail  2  as a whole, the first fixed part  331  covering the outer side of the inner rail  2  contains two horizontal fixed plates in the fixed pulley receiving chamber, which respectively fix the upper and lower ends of the central shaft of the first fixed pulley, and the first fixed part covering the top of the outer rail  1  is provided with two screw holes, the two fixed screws respectively penetrate through the two screw holes to fix the first fixed part on the upper end of the outer rail  1 . To sum up, the first fixed part is just located at the connection between the inner rail  2  and the outer rail  1  and is fixed on the outer rail  1 , while the first fixed part located in the fixed pulley receiving chamber  21  is used to fix the central axis of the first fixed pulley. 
     The central axis of the second fixed pulley is fixed on a side wall of the lower-end second opening groove close to the fixed pulley receiving chamber  21  through a second fixed part, and the central axis of the second fixed pulley and the side wall of the lower-end second opening groove close to the fixed pulley receiving chamber  21  are located in a same plane. To sum up, the first fixed pulley is located in the fixed pulley receiving chamber  21 , and the second fixed pulley is located on the side of the fixed pulley receiving chamber  21  close to the lower-end second opening groove, that is, the central axis of the second fixed pulley and the side wall of the lower-end second opening groove close to the fixed pulley receiving chamber  21  are located in the same plane. The overall winding mode of the conveyor belt is shown in  FIG. 2 . 
     In an illustrated embodiment, the conveyor belt is connected with a belt buckle, a lower end of the belt buckle is connected with a rail trolley of curtain (also referred to as curtain slider, curtain mover), and the rail trolley of curtain is connected with a curtain cloth. When the motor drives the driving wheel to rotate, the driving wheel drives the conveyor belt to rotate, and then drives the curtain cloth to move, so as to realize the opening and closing of the curtain cloth. 
     The unique winding structure adopted by the disclosure ensures that the length of the conveyor belt remains unchanged and the conveyor belt is always in a tensioned state during the opening and closing of the curtain; the curtain guide rail of the disclosure is stretched and retracted to drive the positions of two fixed pulleys to change at the same time, the stretching and retracting operation is simple, the floor area is small, it is conducive to mass industrial production, has a wide range of application, and reduces the transportation cost and production cost. 
     Refer to  FIG. 7  to  FIG. 22 , the telescopic curtain guide rail of the embodiment includes a rail trolley of curtain  4 , the rail trolley of curtain  4  is connected to the conveyor belt  35  and extends out of the outer rail  1  (also referred to as outer guide rail) and the inner rail  2  (also referred to as inner guide rail), the rail trolley of curtain  4  is fixed at a lower end of the conveyor belt  35 , the rail trolley of curtain  4  is movable along an axial direction of the outer rail  1  and the inner rail  2  driven by the conveyor belt  35 . 
     Refer to  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the rail trolley of curtain  4  includes a trolley body  401 , a plurality of first pulleys  402  and a plurality of second pulleys  403 , the plurality of first pulleys  402  and the plurality of second pulleys  403  are rotatably connected to the trolley body  401 , the trolley body  401  includes an upper main body (also referred to as upper trolley body) and a lower main body (also referred to as lower trolley body) connected to the upper main body, both sides of the upper main body are provided with the plurality of first pulleys  402  and the plurality of second pulleys  403 , bottoms of the plurality of first pulleys  402  form a first sliding surface, bottoms of the plurality of second pulleys  403  form a second sliding surface, and the second sliding surface is higher than the first sliding surface. 
     In an illustrated embodiment, the inner rail  2  is provided with a first sliding support surface  202 , the outer rail  3  is provided with a second sliding support surface  302 , when the rail trolley of curtain  4  slides in the inner rail  2 , one of the first pulley  402  and the second pulley  403  is supported on the first sliding support surface  202 , or when the rail trolley of curtain  4  slides in the outer rail  1 , the other one of the first pulley  402  and the second pulley  403  is supported on the second sliding support surface  302 ; and a height difference between the first sliding support surface  202  and the second sliding support surface  302  is matched with a height difference between the second sliding surface and the first sliding surface. 
     The technical principle of the embodiment: the inner rail  2  and the outer rail  1  are respectively provided with the first sliding support surface  202  and the second sliding support surface  302 ; the first pulleys  402  arranged on the rail trolley of curtain form the first sliding surface, and the second pulleys  403  arranged on the rail trolley of curtain form the second sliding surface, the height difference between the first sliding support surface  202  and the second sliding support surface  302  is adapted to the height difference between the second sliding surface and the first sliding surface to eliminate the influence of the height difference between the inner rail  2  and the outer rail  3  on the movement of the rail trolley of curtain (also referred to as curtain rail trolley, curtain mover, curtain slider). 
     Each of the bottom of the first pulley  402  and the bottom of the second pulley  403  refers to one end surface of the supporting pulley of the rail trolley of curtain when in use. The first sliding surface can be understood as that ends of the supporting the plurality of first pulleys  402  is in the same horizontal plane, and the second sliding surface can be understood as that ends of the supporting the plurality of second pulleys  403  is in the same horizontal plane. The first sliding support surface  202  refers to a support surface arranged in the inner rail  2  and matched with the first sliding surface. When the rail trolley of curtain moves in the inner rail, the support surface plays a supporting role against the bottoms of the first pulleys. The second sliding support surface  302  refers to a support surface arranged in the outer rail  1  and matched with the second sliding surface. When the rail trolley of curtain moves in the outer rail, the support surface plays a supporting role against the bottoms of the second pulleys. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the first pulley  402  is arranged coaxially with the second pulley  403 , and a radius of the first pulley  402  is greater than that of the second pulley  403 ; or 
     the first pulley  402  and the second pulley  403  have different rotation axes, the rotation axes of the first pulley  402  and the second pulley  403  are parallel and have a same height, and a radius of the first pulley  402  is greater than that of the second pulley  403 . The radius of the first pulley  402  is larger than that of the second pulley  403 , when used with the curtain guide rail, it cooperates with the first sliding support surface  202  and the second sliding support surface  302 , when the rail trolley of curtain is located on the outer rail  1 , the first pulley  402  has the function of limiting both sides of the rail trolley of curtain because the diameter of the first pulley  402  is larger than that of the second pulley  403  and the distance between them is smaller. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the first pulley  402  is arranged coaxially with the second pulley  403 , or the first pulley  402  and the second pulley  403  have different rotation axes, the first pulley  402  and the second pulley  403  are arranged in a staggered manner in an axial direction of the first pulley  402  and the second pulley  403 , correspondingly, the first sliding support surface  202  and the second sliding support surface  302  are arranged in a staggered manner in the axial direction of the first pulley and the second pulley. Coaxial setting or parallel design of rotating shafts makes the structure of the rail trolley of curtain more compact and more convenient for production and installation. The staggered setting of the first sliding support surface  202  and the second sliding support surface  302  matches the setting of the first pulley  402  and the second pulley  403 , so as to solve the problem of unstable operation between the inner rail  2  and the outer rail  1  of the rail trolley of curtain. 
     In an illustrated embodiment, as shown in  FIG. 7  to  FIG. 22 , the first pulley  402  is arranged coaxially with the second pulley  403 , the first pulley  402  is close to the trolley body  401 , the second pulley  403  is located on a side of the first pulley  402  facing away from the trolley body  401 , and the first pulley  402  is integrally formed with the second pulley  403 . The integrated design makes the structure of the rail trolley of curtain more compact, saves materials and is more convenient for production and installation. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the rail trolley of curtain  4  further includes a plurality of first guide wheels  404 , the first guide wheel  404  is rotatably connected to the upper main body, the first guide wheel  404  transversely penetrates through the upper main body and wheel edges of the plurality of first guide wheels protrude outward relative to sides of the upper main body in a transverse direction, the plurality of first guide wheels  404  are rotatable in the transverse direction, and the first guide wheel  404  is higher than the second sliding support surface  302 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the rail trolley of curtain  4  further includes a plurality of second guide wheels  405 , the second guide wheel  405  is installed on a top of the upper main body and rotatable in the transverse direction, wheel edges of the second guide wheel  405  protrude outward relative to the sides of the upper main body in the transverse direction, the second guide wheel is higher than the first guide wheel  404 , and a radius of the second guide wheel  405  is different from that of the corresponding first guide wheel  404 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the inner rail  2  is provided with a first guide groove  203  therein, the outer rail  1  is provided with a second guide groove  204  therein; when the rail trolley of curtain  4  slides in the inner rail  2 , one of the first guide wheel  404  and the second guide wheel  405  is located in the first guide groove  203  and matched with the first guide groove  203 , or when the rail trolley of curtain  4  slides in the outer rail  1 , the other one of the first guide wheel  404  and the second guide wheel  405  is located in the second guide groove  204  and matched with the second guide groove  204 ; widths of the first guide groove  203  and the second guide groove  204  are different, and a width difference between the first guide groove  203  and the second guide groove  204  is matched with a diameter difference between the first guide wheel  404  and the corresponding second guide wheel  405 . The transverse limit of the rail trolley of curtain can be realized through the combination of the guide wheel and the guide groove, so that the rail trolley of curtain can run smoothly in the transverse direction. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the plurality of first pulleys  402  have a same size and are symmetrically arranged on two sides of the trolley body  401 , and the plurality of second pulleys  403  have a same size and are symmetrically arranged on the two sides of the trolley body  401 . The rail trolley of curtain  4  further includes a plurality of outer pulleys  406  arranged on the two sides of the trolley body  401  in pairs, and the plurality of outer pulleys  406  are located below the first sliding surface and is spaced a predetermined height from the first sliding surface. The outer pulley  406  can make the rail trolley of curtain transition smoothly between the inner rail  2  and the outer rail  1 , and can limit the upward movement of the rail trolley of curtain. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the rail trolley of curtain  4  includes the trolley body  401  and a plurality of pulleys, the trolley body  401  includes an upper main body and a lower main body connected to the upper main body, the upper main body is rotatably installed with the plurality of pulleys, the upper main body is provided with first threading through holes  407 , the lower main body is provided with the second threading through holes  408 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the conveyor belt  35  includes a first conveyor belt and a second conveyor belt, the second conveyor belt is engaged with the driving wheel  31  or the driven wheel  32 , the first conveyor belt is a rope, the first conveyor belt is connected to the second conveyor belt in an annular shape and sleeved on the driving wheel  31  and the driven wheel  32  to make the driving wheel  31  in transmission connection with the driven wheel  32 . The rail trolley of curtain  4  is connected to the first conveyor belt and move on the outer rail  1  and/or the inner rail  2  driven by the first conveyor belt, the upper main body of the rail trolley of curtain  4  is slidable in the outer rail  1  and/or the inner rail  2 , the lower main body of the rail trolley of curtain  4  is located outside the outer rail  1  and the inner rail  2 , the first conveyor belt sequentially passes through the first threading through holes  407  and the second threading through holes  408  to be fixed on the rail trolley of curtain  4 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the first threading through hole  407  and the second threading through hole  408  of the rail trolley of curtain  4  are generally used together with the conveyor belt  35 . The conveyor belt  35  can be composed of the first conveyor belt and the second conveyor belt. Generally, the first conveyor belt is a steel wire rope  501 , the second conveyor belt is a synchronous belt  502 , and the curtain guide rail is generally a curtain guide rail with relatively stretched and retracted sliding between the outer rail  1  and the inner rail  2 . Threading mode of the steel wire rope  501  on the rail trolley of curtain  4 : the steel wire rope  501  sequentially passes through the first end opening  4071  of the first threading through hole  407 , the second end opening  4072  of the first threading through hole  407 , the third threading through hole  409 , the second through hole upper opening  4081  of the second threading through hole  408  and the second through hole lower opening  4082  of the second threading through hole  408 , and then is fixed with the threading fixed device  411 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the curtain guide rail is generally provided with a synchronous wheel, a driven wheel, a conveyor belt  35  and a plurality of rail trolley of curtains  4 . The synchronous wheel and the driven wheel are respectively fixed on both ends of the curtain guide rail, and the lower main body of the rail trolley of curtain  4  extends out of the curtain guide rail. The synchronous belt  502  is disposed on one end of the synchronous wheel (also referred to as second rotating wheel  7 ), The synchronous belt is sequentially connected with the synchronous wheel, the rail trolley of curtain  4 , the driven wheel (also referred to as first rotating wheel  6 ) and the synchronous wheel to form a ring. A number of rail trolley of curtain  4  can be a plurality of rail trolley of curtains  4 , which are connected with the steel wire rope  501  and the synchronous belt  502 , and any one of them is connected with the steel wire rope  501  through the first threading through hole  407  and the second threading through hole  408 . When the length of the curtain guide rail needs to be adjusted, loosening the threading fixed device  411 , pulling the steel wire rope  501  through the first threading through hole  407  of the lower main body, changing the length of the steel wire rope  501  inside the curtain guide rail, so as to change the length of the curtain guide rail, and tightening the threading fixed device  411  after adjustment. The lead structure of the rail trolley of curtain  4  is matched with the curtain guide rail to realize the stretching and retracting of the curtain guide rail, so as to avoid increasing the size of the curtain guide rail. Since one end of the through hole of the lower main body extends outside the curtain guide rail, the length of the steel wire can be temporarily changed through the through hole of the lower main body and the threading fixed device  411 , making the adjustment operation convenient and easy, further, the relative positions of the adjacent rail trolley of curtains  4  can be quickly changed to meet the requirements of double opening curtains. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the first conveyor belt includes a first rope section and a second rope section, the first rope section and the second rope section are separated from each other, and a first end of the first rope section is connected with a first end of the second conveyor belt, a second end of the first rope section passes through the first threading through hole  407  and the second threading through hole  408  and is fixed on the rail trolley of curtain  4 , a first end of the second rope section is connected with a second end of the second conveyor belt, and a second end of the second rope section passes through the first threading through hole  407  and the second threading through hole  408  and is fixed on the rail trolley of curtain  4 . 
     In an illustrated embodiment, the first conveyor belt is a steel wire rope  501 , and the second conveyor belt is a synchronous belt  502 . The steel wire rope  501  includes a first steel wire rope section and a second steel wire rope section. The first steel wire rope section and the second steel wire rope section are separated each other, and two first threading through holes  407  and two second threading through holes  408  are arranged correspondingly; the first steel wire rope section passes through the first threading through hole  407  and the second threading through hole  408 , and the second steel wire rope section passes through the other first threading through hole  407  and the other second threading through hole  408 . Through the above setting, the length of the steel wire rope  501  in the telescopic curtain guide rail can be easily and quickly adjusted. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the rail trolley of curtain  4  further includes a threading fixed device  411 , the threading fixed device  411  is disposed on a side of the lower main body close to the second threading through holes  408  or the threading fixed device  411  is disposed in the second threading through holes  408 , and the threading fixed device  411  fixes the second end of the first rope section and the second end of the second rope section onto the rail trolley of curtain  4 . 
     The threading fixed device  411  is disposed in the second threading through hole  408 , which means that the threading fixed device  411  is partially or completely disposed in the second threading through holes  408 , and the steel wire rope  501  can be fixed by cooperating with the second threading through hole  408 . In an embodiment, the threading fixed device  411  is a hole, ring, threading bolt structure, elastic structure, clamping structure and clamping structure arranged on the lower main body, and the steel wire rope  501  can be fixed on the lower main body through the threading fixed device  411 . In an embodiment, the threading fixed device  411  may not be provided, but the steel wire rope  501  may be fixed by winding or knotting in the second threading through hole  408 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the second threading through hole  408  is a threading bolt hole arranged on the lower main body in a vertical direction, the second threading through hole  408  includes a second through hole upper opening and a second through hole lower opening  4082 , the second through hole lower opening  4082  is disposed on a bottom of the lower main body; the threading fixed device  411  includes threading bolts  4111  and threading nuts  4112 , the threading bolts  4111  are matched with the second threading through holes  408  respectively, the threading nuts  4112  are matched with the second through hole upper openings; the second end of the first rope section and the second end of the second rope section are fixed on the rail trolley of curtain  4  by cooperation of the threading bolts  4111  and threading nuts  4112 . Through the cooperation of threading bolts  4111  and threading nuts  4112 , the steel wire rope  501  can be better fixed in the second threading through hole  408 . The operation of adjusting steel wire rope  501  can be easily carried out by tightening and loosening the threading bolts  4111  and the threading nuts  4112 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, portions of the first conveyor belt are distributed on two sides of the trolley body  401  of the rail trolley of curtain  4 . In an illustrated embodiment, the first conveyor belt is generally a steel wire rope  501 , the steel wire rope  501  sequentially passes through the first threading through hole  407  and the second threading through hole  408 . Since any one of the first threading through hole  407  and the second threading through hole  408  is a threading through hole transversely penetrating through the trolley body  401 , the steel wire rope  501  is distributed on both sides of the trolley body  401 , making it easier for the steel wire rope  501  to pull and fix. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the trolley body  401  of the rail trolley of curtain  4  is further provided with third threading through holes  409 , the third threading through holes  409  transversely penetrate through the trolley body  401  of the rail trolley of curtain  4 , and the first conveyor belt passes through the first threading through hole  407 , the third threading through hole  409  and the second threading through hole  408  sequentially in that order. Specifically, the third threading through hole  409  is disposed between the first threading through hole  407  and the second threading through hole  408 , and the third threading through hole  409  transversely penetrates through the trolley body  401 . The setting of the third threading through holes  409  can make the steel wire rope  501  fit the trolley body  401 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the first threading through hole  407  includes a first end opening  4071  and a second end opening  4072  connected with the first end opening  4071 , the first end opening  4071  is disposed on one side of the upper main body, and the second end opening  4072  is disposed on the other side of the upper main body; the first end opening  4071  disposed on the one side surface of the upper main body is higher than ones of the plurality of pulleys disposed on the one side surface of the upper main body and outward protruding parts of the ones of the plurality of pulleys disposed on the one side surface of the upper main body, and the second end opening  4072  disposed on the other side of the upper main body is lower than the others of the plurality of pulleys disposed on the other side of the upper main body and outward protruding parts of the others of the plurality of pulleys disposed on the other side of the upper main body. The portions of the conveyor belt from the first end opening  4071  to the first rotating wheel  6  and from the first end opening  4071  to the second rotating wheel  7  is higher than the pulleys located on the same side and the outward protruding part of the pulleys located on the same side. 
     The pulleys of the trolley body  401  includes the first pulleys  402 , the second pulleys  403 , the first guide pulleys  404  and the second guide pulleys  405 . The first guide wheel  404  and the second guide wheel  405  are rotatably connected to the upper main body, the first guide wheel  404  transversely penetrates through the upper main body, and in the transverse direction, the wheel edges of the first guide wheels  404  protrude outward relative to the sides of the upper main body; the first pulley  402  and the second pulley  403  are rotatably connected to both sides of the upper main body  401 . The above pulleys located on the same side refers to the first pulleys  402  and the second pulleys  403  are located on the same side; the outward protruding parts of the pulleys located on the same side refers to the outward protruding parts of the first guide wheels  404  and the second guide wheels  405  with respect to the sides of the upper main body. This arrangement can reduce the transverse dimension of the rail trolley of curtain  4  and separate the pulleys of the rail trolley of curtain  4  from the steel wire rope  501  to avoid the steel wire rope  501  blocking and winding the rail trolley of curtain  4  during operation. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the first threading through hole  407  is an arc through hole transversely penetrating through the trolley body  401 , and the first end opening  4071  and the second end opening  4072  are disposed on the two sides of the trolley body  401  in a staggered manner. The first threading through hole  407  is an arc through hole, or the middle part of the first threading through hole  407  is an arc through hole; When the steel wire rope  501  is adjusted through the arc-shaped through hole, the pulling is smoother; the staggered setting of the first end opening  4071  and the second end opening  4072  can reduce the transverse size of the curtain guide pulley  4 , and optimize the transverse and longitudinal stress of the steel wire rope  501  and the threading through hole, making it easier for the steel wire rope  501  to pull and fix. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the telescopic curtain guide rail further includes a curtain guide rail fixed device  100 , the curtain guide rail fixed device  100  includes a guide sleeve  101 , and the guide sleeve  101  is hollow tubular structure with openings at both ends, and the guide sleeve  101  is sleeved outside a connection between the outer rail  1  and the inner rail  2 , the connecting end of the outer rail  1  is inserted into the guide sleeve  101  from the second end of the guide sleeve  101  and matched with the guide sleeve  101 , the free end of the outer rail  1  extends out from the guide sleeve  101 , the inner rail  2  is inserted into the guide sleeve  101  from the first end of the guide sleeve  101  and matched with the guide sleeve  101 , and the connecting end of the inner rail  2  is inserted into the outer rail  1 , the free end of the inner rail  2  extends out of the guide sleeve  101 , and the rail trolley of curtain  4  can pass through the guide sleeve  101  when moves between the outer rail  1  and the inner rail  2 . 
     In an illustrated embodiment, the upper main body of the rail trolley of curtain  4  is located in the outer rail  1  and the inner rail  2 , the lower main body of the rail trolley of curtain  4  is located outside the outer rail  1  and the inner rail  2 , and the upper main body and the lower main body move along both ends of the inner rail  2  and the outer rail  1 . When in use, the length of the conveyor belt is fixed, which can limit the stretching of the curtain guide rail, when used in conjunction with the curtain guide rail fixed device  100 , the telescopic curtain guide rail can be fixed to prevent it from stretching and retracting inward. The free ends of the outer rail  1  and the inner rail  2  refer to the ends of the outer rail  1  and the inner rail  2  relative to the ends matching with the guide sleeve  101 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, a bottom surface of the guide sleeve  101  is provided with a first support surface  102  and a second support surface  103 , the first support surface  102  extends inward along an axial direction of the guide sleeve  101  from the first end of the guide sleeve  101 , the second support surface  103  extends inward along the axial direction of the guide sleeve  101  from the second end of the guide sleeve  101 , the first support surface  102  is connected with the second support surface  103 , the first support surface  102  is higher than the second support surface  103 , and a step is formed at a connection between the first support surface  102  and the second support surface  103 , the first support surface  102  supports the inner rail  2 , the second support surface  103  supports the outer rail  1 , the outer rail  1  abuts against at the step, a height difference of bottom surfaces of the outer rail  1  and the inner rail  2  is matched to a height difference between the second support surface  103  and the first support surface  102 . The outer rail  1  abuts against at the step here can be understood as that the outer rail  1  is connected with the step, and the step resists the movement of the outer rail  1  to the first end of the guide sleeve  101 . The first support surface  102  is higher than the second support surface  103  with reference to the bottom surface of the guide sleeve  101 . The above mentioned higher in the disclosure refers to taking the plane of the outer surface at the bottom of the guide sleeve  101  as a reference. 
     The second support surface  103  can be matched with the outer rail  1 , the outer rail  1  is limited by the step where the first support surface  102  is connected with the second support surface  103 , and the first support surface  102  can be matched with the inner guide rail  2 , the inner guide rail  2  can slide along the first support surface  102  from the first end of the guide sleeve  101  and extend into the outer rail  1 , adjusting the position where the inner rail  2  extends into the outer rail  1  to achieve the required length of the curtain guide rail, then, the curtain guide rail can be fixed with the fixed component  113 . The fixed component  113  can match with the guide sleeve  101  to restrict the relative stretching and retracting of the inner rail  2  and the outer rail  1  inward. The curtain guide rail fixed device  100  can also be used in conjunction with curtain guide rail conveying mechanisms such as conveyor belts or conveyor ropes, when the curtain guide rail transmission mechanism is in use, the length of the curtain guide rail transmission mechanism is fixed, which can limit the outward stretching of the curtain guide rail. Therefore, the curtain guide rail fixed device  100  and the curtain guide rail transmission mechanism can fix the telescopic curtain rod guide rail to prevent it from stretching outward and retracting inward. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the bottom surface of the guide sleeve  101  is provided with a through groove  108  penetrating the first support surface  102  and the second support surface  103 , a bottom of the inner rail  2  is provided with a first sliding opening  201  along the axial direction, a bottom of the outer rail  3  is provided with a second sliding opening  301  along the axial direction, the first sliding opening  201  is communicated with the second sliding opening  301 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, two ends of the through groove  108  are respectively communicated with the first sliding opening  201  and the second sliding opening  301 . Specifically, the first sliding opening  201  is wider than the second sliding opening  301  and is a rectangular opening. The first sliding opening  201  and the second sliding opening  301  are respectively arranged at the middles of the bottoms of the inner rail  2  and the bottom of the outer rail  1 . The first sliding opening  201  and the second sliding opening  301  are communicated with each other and are communicated with the through groove  108 , so that the curtain guide rail components such as the rail trolley of curtain  4  protruding outside the curtain guide rail can move between the inner rail  2  and the outer rail through the guide sleeve  101 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the through groove  108  includes a first through section  109  and a second through section  110 , the first through section  109  is communicated with the second through section  110 , positions of the first through section  109  and the second through section  110  correspond to positions of the first support surface  102  and the second support surface  103  respectively, a width of the first through section  109  close to the first end of the guide sleeve  101  is greater than a width of the first sliding opening  201 , a width of the first through section  109  close to the second through section  110  is matched with the width of the first sliding opening  201 . 
     In an illustrated embodiment, a width of the second through section  110  is matched with a width of the second sliding opening  301 . Specifically, the first sliding opening  201  is wider than the second sliding opening  301  and is a rectangular opening. The first sliding opening  201  and the second sliding opening  301  are respectively arranged in the middle of the bottom of the inner rail  2  and the bottom of the outer rail  1 . The width of the first sliding opening  201  refers to the distance between its two sides parallel to the axial direction of the inner rail  2 ; the width of the second sliding opening  301  refers to the distance between its two sides parallel to the axial direction of the outer rail  1 . When in use, the width of the first through section  109  close to the first end of the guide sleeve  101  is greater than the first sliding opening  201  of the inner rail  2 , and the width of the first through section  109  close to the second through section  110  corresponds to the width of the first sliding opening  201  of the inner rail; the width of the second through section  110  corresponds to the width of the first sliding opening  201  of the outer rail  1 . The communication among the through groove  108  of the guide sleeve  101 , the first sliding opening  201  of the inner rail  2  and the first sliding opening  201  of the outer rail  1  is smoother, and the curtain guide rail components such as the rail trolley of curtain  4  pass through them more smoothly. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, the plurality of second pulleys  403  are rotatably installed on the rail trolley of curtain  4 , the guide sleeve  101  further includes transition tables  112 , the transition tables  112  protrude upward relative to the first sliding support surface  202 , the transition tables are extended outward along the axial direction of the guide sleeve  101  from the connection between the first sliding support surface  202  and the second sliding support surface  302 , an inner surface of the bottom of the outer rail  1  is provided with a second sliding support surface  302 , the second sliding support surface  302  is axially extended from the connecting end of the outer rail  1  towards the other end of the outer rail  1 , the second sliding support surface  302  is higher than the inner surface of the bottom of the outer rail  1 ; when the outer rail  1  is matched with the guide sleeve  101 , the transition tables  112  are butted and matched with the second sliding support surface  302  in the axial direction of the guide sleeve  101 , and the second sliding support surface  302  is higher than the transition tables  112 , the second pulley  403  can slidable upward from the transition table  112  to the second sliding support surface  302  or downward from the second sliding support surface  302  to the transition table  112 . 
     The height of the transition table  112  (related to the first support surface  102 ) is lower than that of the second sliding support surface  302  (related to the inner bottom surface of the outer rail  1 ). The height of the transition table  112  is generally one-half of the height of the second sliding support surface  302 . This arrangement can solve the problem that when the height of the second sliding support surface  302  is high, the pulleys of the rail trolley of curtain  4  move on second sliding support surface  302  are unstable. For example, it can solve the problem that when the height of the second sliding support surface  302  is higher than the pulley radius of the rail trolley of curtain  4 , the operation of the rail trolley of curtain  4  may be hindered. Therefore, the transition table  112  can make the pulleys of the rail trolley of curtain  4  move on the second sliding support surface  302  more stable and run more smoothly. 
     In a further embodiment, the rail trolley of curtain is fixed at the lower end of the conveyor belt, the rail trolley of curtain extends out of the outer rail and the inner rail, the rail trolley of curtain can move along the axial direction of the outer rail and the inner rail driven by the conveyor belt, and the rail trolley of curtain can be rotatably installed with the plurality of second pulleys, the second pulleys can slidable upward from the transition table to the second sliding support surface or downward from the second sliding support surface to the transition table. 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, an upper part of the guide sleeve  101  is provided with first guide rails  104  and second guide rails  105 , the first guide rails  104  and the second guide rails  105  are respectively disposed on the first support surface  102  and the second support surface  103  and extend along the axial direction of the guide sleeve  101 , the first guide rails  104  are connected to the second guide rails  105 , connections of the first guide rails  104  and the second guide rails  105  are provided with steps, the first guide rails  104  are matched with a top of the inner rail  2  to fix both sides of the inner rail  2  relative to the guide sleeve  101 . 
     The second guide rails  105  are matched with a top of the outer rail  1  to fix both sides of the outer rail  1  relative to the guide sleeve  101 . The first guide rail  104  and the second guide rail  105  are located above the first support surface  102  and the second support surface  103  respectively and extend along the axial direction of the guide sleeve  101 , which can be understood as that the first guide rail  104  and the second guide rail  105  are located in the guide sleeve  101  and away from the corresponding top parts of the first support surface  102  and the second support surface  103 . When in use, the shape of the first guide rail  104  is matched with the top end of the inner rail  2 , the shape of the second guide rail  105  is matched with the top end of the outer rail  1 , and the steps can abut against the connecting end of the outer rail  1 , so that the guide sleeve  101  can limit both sides of the inner rail  2 , both sides and the connecting end of the outer rail  1 . 
     As shown in  FIG. 7  to  FIG. 22 , in an illustrated embodiment, an outer surface of the bottom of the guide sleeve  101  is provided with a transition surface  111 , the transition surface  111  is disposed on a back of the first support surface  102 , one end of the transition surface  111  close to the connection between the first support surface  102  and the second support surface  103  is matched with the outer rail  1 , the other end of the transition surface  111  is matched with the inner rail  2 , and a height difference between the one end of the transition surface  111  matched with the outer rail  1  and the other end of the transition surface  111  is matched with a height difference between the inner rail  1  and the outer rail  2 . 
     A thickness of the bottom surface of the guide sleeve  101  gradually becomes thinner from the connection between the first support surface  102  and the second support surface  103  to the first end of the guide sleeve  101 , the outer surface of the bottom of the guide sleeve  101  is provided with the transition surface  111 , the transition surface  111  is disposed on the back of the first support surface  102  and on the both sides of the through groove  108 . When the bottom surface of the guide sleeve  101  is placed on a horizontal plane, the transition surface  111  is arranged obliquely relative to the horizontal plane, and a height of the transition surface  111  close to the connection between the first support surface  102  and the second support surface  103  is higher than a height of the transition surface  111  close to the first end of the guide sleeve  101 . The one end of the transition surface  111  close to the connection between the first support surface  102  and the second support surface  103  is matched with the outer rail  1 , the other end of the transition surface  111  is matched with the inner rail  2 , and the height difference between the one end of the transition surface  111  matched with the outer rail  1  and the other end of the transition surface  111  is matched with the height difference between the inner rail  1  and the outer rail  2 . It can be understood that the other end of the transition surface  111  touches the outer surface of the bottom of the inner rail  2 , but it can slide relatively or be slightly spaced. The setting of the transition surface  111  enables the outer pulley  406  of the rail trolley of curtain  4  to transition smoothly among the guide sleeve  101 , the inner rail  2  and the outer rail  1  when the curtain guide rail is used with the rail trolley of curtain  4 . When the bottom surface of the guide sleeve is placed on the horizontal plane, the transition surface is inclined relative to the horizontal plane, and the height of the transition surface close to the connection of the first support surface and the second support surface is higher than the height of the transition surface close to the first end of the guide sleeve. 
     As shown in  FIG. 7  through  FIG. 22 , in an embodiment, the guide sleeve  101  further includes a first mating surface  106  and a second mating surface  107 , the first mating surface  106  extends inward along the axial direction of the guide sleeve  101  from both sides and a top surface of the first end of the guide sleeve  101  and together with the first support surface  102  form an annular surface with an opening at a bottom thereof, the second mating surface  107  extends inward along the axial direction of the guide sleeve  101  from two side surfaces and a top surface of the second end of the guide sleeve  101  and together with the second support surface  103  form an annular surface with an opening at a bottom thereof. Compared with the second mating surface  107 , the first mating surface  106  is closer to a central axis of the guide sleeve  101 , in the axial direction of the guide sleeve  101 , the first mating surface  106  is connected with the second mating surface  107 , and a step is formed at a connection between the first mating surface  106  and the second mating surface  107 . 
     Specifically, an annular surface surrounded by the first mating surface  106  and the first support surface  102  is located in an annular surface surrounded by the second mating surface  107  and the second support surface  103 . The distance between the two annular surfaces corresponds to the height difference between the inner guide rail  2  and the outer rail  1  of the curtain guide rail, so that one end of the inner guide rail  2  can smoothly pass through the guide sleeve  101  and be inserted into the outer rail  1 , so as to ensure that the curtain guide rail components such as the rail trolley of curtain  4  can make a smooth transition between the interior of the inner rail  2 , the interior of the outer rail  1  and the interior of the guide sleeve  101 . Compared with the second mating surface  107 , the first mating surface  106  is closer to the central axis of the guide sleeve  101 , which can be understood as two coaxial semi-annular surfaces spaced internally and externally; the two side surfaces and top surfaces of the first end and the two side surfaces and top surfaces of the second end are directed to the two sides and the top surface inside the guide sleeve  101 . 
     As shown in  FIG. 7  to  FIG. 22 , in an embodiment, the curtain guide rail fixed device  100  further includes a fixed component  113 , the fixed component  113  passes through an outer housing of the guide sleeve  101  from outside of the guide sleeve  101  and partially extends into the guide sleeve  101 , the fixed component is connected with the inner rail and/or the outer rail to fix the inner rail and/or the outer rail relative to the guide sleeve. 
     In an embodiment, the fixed component  113  can pass through the housing of the guide sleeve  101  from the top surface, bottom surface and two sides of the guide sleeve  101 , and partially extend into the guide sleeve  101 . The preferred solution is to pass through the housing of the guide sleeve  101  from the top surface of the guide sleeve  101 . 
     In an embodiment, the fixed component  113  includes a spiral connection fixing, a clamping fixing, a snap spring fixing, a spring fixing and a clamping fixing structure, etc. Specifically, the fixed component  113  is a bolt fixed component. The bolt fixed component includes a fixed bolt  114 , a fixed bolt hole  115  and a T-shaped nut  116 . The upper part of the T-shaped nut  116  is smaller than the lower part. A limit part  117  with an opening at one hollow end is arranged in the guide sleeve  101 , and the opening faces into the guide sleeve  101 , the upper part of the T-shaped nut  116  can be nested in the limit part  117 , and the fixed bolt  114  passes through the limit part and is connected with the T-shaped nut  116  through the fixed bolt hole  115 ; when the fixed bolt  114  and the T-shaped nut  116  rotate and fit in the fixed bolt hole  115 , the limit part  117  limits the upper part of the T-shaped nut  116 , and the T-shaped nut  116  can move outside the guide sleeve  101 . The T-shaped nut  116  can better fix the inner rail  2  and the guide sleeve  101 . 
     Referring to  FIGS. 7-22 , in an embodiment, the curtain guide rail fixed device  100  further includes a fixed component  113 , which passes through the housing of the guide sleeve  101  from the outside of the guide sleeve  101  and partially extends into the guide sleeve  101 . The fixed component  113  is connected with the inner rail  2  and/or the outer rail  1  to fix the inner rail  2  and/or the outer rail  1  relative to the guide sleeve  101 . The preferred solution is to pass through the housing of the guide sleeve  101  from the top surface of the guide sleeve  101 . In an embodiment, the fixed component  113  includes a helical connection fixing, a clamping fixing, a snap spring fixing, a spring fixing and a clamping fixing structure, etc. 
     Referring to  FIGS. 7-22 , in an embodiment, the fixed component  113  is a fixed bolt  114 , the guide sleeve  101  is also provided with a fixed bolt hole matched with the fixed bolt  114 , the fixed bolt hole passes through the guide sleeve  101 , and the fixed bolt  114  can extend into the guide sleeve  101  through the fixed bolt hole to fix the inner guide rail  2 . 
     Referring to  FIGS. 7-22 , in an embodiment, the fixed component  113  includes a fixed bolt  114  and a fixed plate, the fixed plate is disposed in the guide sleeve  101 , and both the guide sleeve  101  and the fixed plate are provided with fixed bolt holes matched with the fixed bolt  114 , under the rotating cooperation of the fixed bolt  114  and the fixed bolt holes, the fixed plate moves inward to press and fix the inner rail  2  or moves outward to clamp and fix the inner rail  2  between the fixed plate and the guide sleeve  101 . In an embodiment, the fixed component  113  is a bolt fixed component, the bolt fixed component includes a fixed bolt  114 , a fixed bolt hole  115  and a T-shaped nut  116 . The upper part of the T-shaped nut  116  is smaller than the lower part. A limit part  117  with an opening on one hollow end is arranged in the guide sleeve  101 , the opening faces into the guide sleeve  101 , and the upper part of the T-shaped nut  116  can be nested in the limit part  117 , the fixed bolt  114  penetrates the limit part and is connected with the T-shaped nut  116  through the fixed bolt hole  115 . When the fixed bolt  114  and the T-shaped nut  116  rotate and fit in the fixed bolt hole  115 , the limit part  117  limits the upper part of the T-shaped nut  116 , and the T-shaped nut  116  can move outside the guide sleeve  101 . The T-shaped nut  116  can better fix the inner rail  2  and the guide sleeve  101 . 
     As shown in  FIG. 23  to  FIG. 32 , in an embodiment, the telescopic curtain guide rail further includes an adjusting component fixedly connected with the first fixed pulley  33  and/or the second fixed pulley  34 , the adjusting component is configured to cooperate with the first fixed pulley  33  and/or the second fixed pulley  34  to drive the first fixed pulley  33  and/or the second fixed pulley  34  to move, thereby to tension or loosen the conveyor belt, the adjusting of length of the conveyor belt is realized. Avoiding that the length of the conveyor belt is too long and the conveyor belt will run out. It can also avoid that the conveyor belt is too short and affect the smoothness of operation. 
     The telescopic curtain guide rail provided by the disclosure realizes the movement of the fixed pulley through the adjusting component, thus realizing the adjustment of the length of the conveyor belt  35 , realizing the change of the tension of the conveyor belt  35 , and overcoming the problem that it is difficult to accurately control the length of the conveyor belt  35  during the assembly of the curtain guide rail. After the curtain guide rail is assembled, the fine adjustment of the length of the conveyor belt  35  can be realized through the adjustment of the adjusting component. 
     As shown in  FIG. 23  to  FIG. 32 , in an embodiment, the adjusting component includes an adjusting nut  311  and an adjusting screw  312  matched with the adjusting nut  311 , and a cooperation of the adjusting screw  312  and the adjusting nut  311  drives the first fixed pulley  33  and/or the second fixed pulley  34  to move, so as to control the tension of the conveyor belt. In this embodiment, one of the first fixed pulley  33  or the second fixed pulley  34  can be adjusted separately through the adjusting component, or the first fixed pulley  33  and the second fixed pulley  34  can be adjusted simultaneously through the adjusting component. 
     As shown in  FIG. 23  to  FIG. 32 , in an embodiment, the adjusting component further includes a stopper  51 , upper and lower ends of the adjusting nut  311  extend towards the stopper  51  and are connected with the stopper  51 , the first fixed pulley and/or the second fixed pulley are disposed in an installation area. In an embodiment, the adjusting component adjusts the tightness of the conveyor belt  35  by adjusting the movement of the first fixed pulley  33 . In this embodiment, the first fixed pulley  33  is fixed on the adjusting component, specifically, the first fixed pulley  33  is installed and fixed in the installation area formed between the stopper  51  and the adjusting nut  311 , the side of the stopper  51  close to the first fixed pulley is an arc surface, and the conveyor belt  35  on two sides of the first fixed pulley  33  are respectively located on two sides of the stopper  51 . In this embodiment, by setting the stopper  51 , it can better fix the first fixed pulley  33  and realize that the adjusting component can drive the first fixed pulley  33  to move. The side of the stopper  51  close to the adjusting nut  311  is an arc surface, which can avoid the friction damage of the stopper  51  to the conveyor belt  35 . 
     Referring to  FIGS. 23-32 , in an embodiment, the telescopic curtain guide rail includes the guide sleeve  101 , which is a hollow tubular structure with openings at both ends, the bottom surface of the guide sleeve  101  is formed with the first support surface  102  and the second support surface  103 , the first support surface  102  is higher than the second support surface  103 , and a step  1023  is formed at the connection between the first support surface  102  and the second support surface  103 , the guide sleeve  101  is sleeved at one end of the outer rail  1  close to the inner rail  2 , the inner rail  2  is connected with the first support surface  102 , the outer rail is connected with the second support surface  103 , the end of the outer rail  1  abuts against the step  1023 , the adjusting component is located in the guide sleeve  101 , and the adjusting component is slidably connected with the guide sleeve  101 . In this embodiment, the inner rail  2  and the outer rail  1  are connected through the guide sleeve  101  to realize the smooth transition between the inner rail  2  and the outer rail  1 , so as to ensure that the curtain can be pulled smoothly during normal use. The setting of the guide sleeve  101  can not only transition the connection between the inner rail  2  and the outer rail  1 , making the guide rail more beautiful, but also realize the relative movement of the adjusting component, so as to drive the movement of the first fixed pulley  33  and realize the control of the tension of the conveyor belt. 
     Referring to  FIGS. 23-32 , the guide sleeve  101  is provided with an adjusting installation groove  1011 , the adjusting installation groove  1011  is arranged in the space surrounded by the first support surface  102 , the adjusting component is fixed in the adjusting installation groove  1011 , one end of the adjusting installation groove  1011  is provided with an opening, the other end of the adjusting installation groove  1011  is provided with a baffle  1012 , the opening is arranged at one end close to the second support surface  103 , and the baffle  1012  is provided with a through hole  1013  that can insert the screw. The setting of the baffle  1012  can better limit the adjusting component to the adjusting installation groove  1011 . The setting of the opening enables the conveyor belt  35  to extend into the adjusting installation groove  1011  and connect with the first fixed pulley, and the conveyor belt  35  on the other side of the first fixed pulley can also extend out from the adjusting installation groove  1011 . The adjusting screw is matched with the adjusting nut through the through hole. When the adjusting screw to rotate, it can drive the adjusting component away from or close to the baffle. The belt tension is adjusted by adjusting the distance between the adjusting component and the baffle  1012 . 
     Referring to  FIGS. 23-32 , in an embodiment, the top wall of the adjusting installation groove is provided with the first opening  1014 , and the bottom wall of the adjusting installation groove is provided with the second opening  1015  opposite to the first opening  1014 , and the first fixed pulley and/or the second fixed pulley are fixed in the installing area of the adjusting component through the fixed shaft  3331 , and the two ends of the fixed shaft  3331  are respectively extended into the first opening  1014  and the second opening  1015 . 
     Referring to  FIGS. 23-32 , in an embodiment, the outer rail  1  includes an upper-end first closed groove  12  and a lower-end first opening groove  13 , the side wall of the lower-end first opening groove  13  is provided with a first outer rail inner wall  14  and a second outer rail inner wall  15  extending inwardly towards the groove, and a first insertion gap  131  is formed between the bottom wall of the upper-end first closed groove  12  and the first outer rail inner wall  14 , a second insertion gap  132  is formed between the bottom wall of the lower-end first opening groove  13  and the second outer rail inner wall  15 , and the conveyor belt  35  is located between the first outer rail inner wall  14  and the second outer rail inner wall  15 ; the inner rail  2  includes an upper-end second closed groove and a lower-end second opening groove. the bottom wall of the upper-end second closed groove is inserted into the first insertion gap  131 , and the bottom wall of the lower-end second open groove is inserted into the second insertion gap  132 . This mode can realize better nesting of the inner rail  2  and the outer rail  1 , better cooperation between the inner rail  2  and the outer rail  1 , and better stability of curtain guide rail. 
     Referring to  FIGS. 23-32 , in an embodiment, the end of the first outer rail inner wall  14  abuts against the top wall of the adjusting installation groove  1011 , and the end of the second outer rail inner wall  15  abuts against the bottom wall of the adjusting installation groove  1011 . There is a third insertion gap  133  between the bottom wall of the adjusting installation groove  1011  and the first support surface  102 , and the bottom wall of the lower-end second opening groove passes through the third insertion gap  133  and is inserted into the second insertion gap  132 . In this embodiment, the adjusting component is fixed by the adjusting installation groove  1011  to achieve a more stable effect. At the same time, the top wall and bottom wall of the adjusting installation groove can match with the first outer rail inner wall  14  and the second outer rail inner wall  15 , so that the end of the outer rail  1  can better match with the inner rail  2  in the guide sleeve  101 . 
     Referring to  FIGS. 23-32 , in an embodiment, when the inner rail  2  is matched with the outer rail  1 , the first side wall  26  of the inner rail  2  divides the lower-end first opening groove into the first cavity and the second cavity, the second fixed pulley  34  is fixed on the inner rail  2  through the second fixed component, the second fixed component is provided with a connecting clamp  27 , and the connecting clamp  27  clamps the end of the first side wall  26 . The portions of the conveyor belt  35  located on two sides of the second fixed pulley  34  are located in the first cavity and the second cavity respectively. In this embodiment, the second fixed pulley  34  is fixed by the connecting clamp  27 . After the connecting clamp  27  clamps the end of the first side wall  26 , it can be further locked by screws to further ensure the stability of the curtain guide rail. 
     Referring to  FIGS. 23-32 , the conveyor belt  35  includes a first connecting section  351  and a second connecting section  352  connected each other. The first connecting section  351  and the second connecting section  352  are connected in a head-to-tail manner. The first connecting section  351  is matched with the driving wheel  31 , the second connecting section  352  is wound on the first fixed pulley  33  and the second fixed pulley  34 , and the second connecting section  352  is also matched with the driven wheel. In an embodiment, the second connecting section  352  is matched with the driven wheel. In this embodiment, the belt thickness of the first connecting section  351  is greater than that of the second connecting section  352 . The belt thickness referred to in this embodiment is not limited to the thickness of the belt, so it can also refer to the diameter of the steel wire or rope. 
     For example, when the first connecting section  351  and/or the second connecting section  352  are flat drive belt (E. G., a belt, a flat rope), the belt thickness refers to the direct thickness of the belt or flat rope, and when the first connecting section  351  and/or the second connecting section  352  are steel wire or rope with a circular section, the belt thickness refers to the diameter of the steel wire or rope. 
     In this embodiment, the belt thickness of the first connecting section  351  is greater than that of the second connecting section  352 , so that the first connecting section  351  matched with the driving wheel  31  is thicker, which can better drive and avoid wear. The belt thickness of the second connecting section  352  wound on the first fixed pulley  33  and the second fixed pulley  34  is thinner, which can save the space of the guide rail and realize more lightweight and beautiful guide rail. 
     In an embodiment, the first connecting section  351  is one or more selected from the group consisting of a belt, a steel wire and a rope; and the second connecting section  352  is one or more selected from the group consisting of a belt, a steel wire and a rope. 
     For those skilled in the art, various other corresponding changes and modifications can be made according to the technical scheme and concept described above, and all these changes and modifications should fall within the protection scope of the appended claims of the disclosure.