Roller blind drive device preventing accident due to drive cord

Proposed is a roller blind drive device preventing an accident due to a drive cord, the drive device being configured to lower or raise a curtain fabric by performing forward/reverse rotation of a drum on which the curtain fabric is wound, the drive device including a fixed part, a rotating part mounted rotatably to the fixed part and configured to perform the forward/reverse rotation of the drum, a circular drive cord having a front cord and a rear cord, and a manipulating part connected to the drive cord exposed to the lower side of the fixed part. Accordingly, the drive cord is covered so as not to be seen from the outside, and any one drive cord of the two drive cords is held by the rotating manipulation of the manipulation tube.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2022-0066847, filed May 31, 2022, the entire contents of which are incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates generally to a roller blind drive device which lowers or raises a curtain fabric by performing the forward/reverse rotation of a drum on which the curtain fabric is wound. More particularly, the present disclosure relates to a roller blind drive device preventing an accident due to a drive cord in which a drive cord including two cords is covered so as not to be seen from the outside, thereby preventing a dangerous situation in which the drive cord is wrapped around a person's body, and one cord of the two cords is held according to the rotating manipulation of a manipulation tube, thereby lowering or raising the curtain fabric only by a simple manipulation of pulling the manipulation tube down.

Description of the Related Art

Generally, a roller blind is configured such that a curtain fabric which blocks light is wound on a drum, and the curtain fabric is lowered or raised according to forward/reverse rotation of the drum.

That is, a drive device which transmits forward/reverse rotational force generated by a user to the drum is provided on one side or each of opposite sides of the roller blind.

Such a drive device is basically composed of a pulley connected to the drum so as to rotate same, and a drive cord connected to the pulley so as to receive a rotational force from a user.

Here, the drive cord connected to the pulley is made in a circular closed type of drive cord, and includes two cords hanging on the pulley in a loop type toward the lower side of the roller blind.

That is, when a user pulls down one drive cord, the drum is rotated forward and the curtain fabric is lowered, but when a user pulls down the other drive cord, the drum is rotated reversely and the curtain fabric is raised.

As for such a roller blind, the two cords are connected to each other in a loop type, and unless otherwise indicated, it is impossible to know which cord is responsible for forward/reverse rotation, which causes inconvenience.

In addition, for the convenience of a user's manipulation, the cords are extending up to the lower part of a window by having a relatively long length, and thus when the window is opened, the curtain fabric flaps due to the outside air.

Particularly, there is a serious problem that the drive cords may be wrapped around a person's body due to the intention of a user or the carelessness of children, which may lead to death.

Accordingly, in order to solve such problems, the following patent document discloses a technology in which two drive cords are covered so as not to be exposed to the outside and any one of the two cords is held to be pulled.

That is, the drive cords are covered and are prevented from being exposed to the outside, and thus a dangerous situation in which the drive cords may be wrapped around a user's body can be prevented.

However, in order to hold any one of the two drive cords, a process in which the one cord is pulled down by being slanted forward or backward and is raised in a straightly standing state is required to be performed.

Furthermore, the holding force of the drive cord varies depending on an inclined angle, and thus when the drive cord is not inclined at a proper angle, the drive cord may slip and may not be manipulated.

Document of Related Art

(Patent Document 1) Korean Patent No. 10-2077404 Invention Title: DRIVING DEVICE HAVING PROTECTIVE COVER FOR ROLLER BLIND CORD

SUMMARY OF THE INVENTION

Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure is intended to propose a roller blind drive device preventing an accident due to a drive cord in which a holding member is moved by the rotating manipulation of a manipulation tube and holds any one cord of two cords such that a curtain fabric can be lowered or raised only by a simple manipulation of pulling the manipulation tube down.

In addition, the present disclosure is intended to propose a roller blind drive device preventing an accident due to a drive cord in which a holder of the holding member holding a drive cord presses the drive cord such that the drive cord slants downward, so that the associated drive cord is securely held only when the drive cord is pulled downward, and the holding of the associated drive cord is automatically released when the drive cord is returned to a raised position, thereby lowering or raising the curtain fabric to a desired position only by repeating the pulling manipulation.

Furthermore, the present disclosure is intended to propose a roller blind drive device preventing an accident due to a drive cord in which a tension spring allows the drive cord to be maintained in taut tension and allows the manipulation tube lowered by pulling to be automatically returned to a raised position, whereby the convenience of use is improved and a neat and tidy interior is created, thereby increasing satisfaction of a user overall.

In order to achieve the above objectives, according to one aspect of the present disclosure, there is provided a roller blind drive device preventing an accident due to a drive cord, the drive device being configured to lower or raise a curtain fabric1by performing forward/reverse rotation of a drum2on which the curtain fabric1is wound, the drive device including a fixed part10disposed fixedly at a side of the drum2; a rotating part20mounted rotatably to the fixed part10and configured to perform the forward/reverse rotation of the drum2such that the curtain fabric1is lowered or raised; a circular drive cord30having a front cord31and a rear cord32which are connected to the rotating part20in an infinite loop so as to be rotated in a same direction and hang toward a lower side of the fixed part10such that the front cord31and the rear cord32are spaced apart from each other; and manipulating part40connected to the drive cord30exposed to the lower side of the fixed part10, the manipulating part40being configured to perform forward/reverse rotation of the drive cord30by selectively gripping the front cord31or the rear cord32according to rotating and pulling manipulations of the manipulating part40performed by a user.

In this case, according to the present disclosure, the fixed part10may include: a fixed casing11having an inner diameter to receive the rotating part20and having a path provided on a lower end of the fixed casing11by having a predetermined size such that the drive cord30is connected to the rotating part20and the manipulating part40, and a fixed shaft12being inserted into and mounted to a center of the fixed casing11and supporting the rotating part20such that the rotating part20is rotatable.

In addition, according to the present disclosure, the fixed casing11may include: a cord guide11aprotruding on each of front and rear sides of the lower end of the fixed casing11by having a predetermined length such that the drive cord30connected to the rotating part20is aligned with the manipulating part40, and a manipulation guide11bconnected to and protruding on one side of the guide protrusion part11ain a front-to-rear direction such that the manipulating part40is returned to an original position.

Furthermore, according to the present disclosure, the rotating part20may include: a rotating wheel21being rotatably mounted inside the fixed part10and connected with the drive cord30so as to receive forward/reverse rotational force therefrom, and a drum holder22being mounted to the rotating wheel21by being engaged therewith, and configured to being inserted into a center of one side of the drum2so as to perform the forward/reverse rotation of the drum2.

Additionally, according to the present disclosure, the manipulating part40may include: a manipulation cover41disposed to cover the drive cord30exposed to the lower side of the fixed part10, and receiving the front and rear cords31and32of the drive cord30such that the front and rear cords31and32are separated from each other in a front-to-rear direction and move upward and downward; a holding member42being mounted to a center of the manipulation cover41so as to move slidably forward and backward, the holding member42being configured to press and hold the front and rear cords31and32according to the forward and backward movements of the holding member42, respectively; a rotating member43being rotatably mounted to a lower end of the manipulation cover41and connected to the holding member42so as to move the holding member42forward and backward; a manipulation tube44being mounted to a lower end of the rotating member43and receiving the drive cord30so as to receive rotational force of the rotating member43and downward movement force of the front and rear cords31and32from a user; a connecting member45being mounted in a center of the manipulation tube44and connected to the drive cord30in an infinite loop; and a tension spring46being mounted to a center of a lower end of the manipulation tube44and connected to the connecting member45, the tension spring46allowing the drive cord30to be maintained in predetermined tension by pulling the connecting member45down and allowing the manipulation cover41to be returned to a raised position adjacent to the fixed part10.

In addition, according to the present disclosure, the manipulation cover41may include: an inner cover41adisposed on one side of a lower part of the fixed part10and receiving the front and rear cords31and32, the holding member42, and the rotating member43, and an outer cover41bbeing mounted to the inner cover41ato cover the inner cover41a, the outer cover41brestricting the front and rear cords31and32, the holding member42, and the rotating member43such that the front and rear cords31and32, the holding member42, and the rotating member43are mounted in the inner cover41a.

Furthermore, according to the present disclosure, the manipulation cover41may include: a cover guide41cprotruding on an upper end of each of the inner and outer covers41aand41b, the cover guide41cbeing guided to be returned to an original position by interfering with a lower end portion of the fixed part10; separating protrusion parts41dprotruding on upper and lower ends of one surface of the inner cover41aby having predetermined lengths, the separating protrusion parts41dseparating the front and rear cords31and32from each other such that the front and rear cords31and32move upward and downward; a guide rail41eprotruding on a center of one surface of each of the inner and outer covers41aand41bsuch that the guide rail41eis horizontal in the front-to-rear direction, the guide rail41esupporting the holding member42such that the holding member42slides forward and backward; an elastic plate41fprotruding on a center of the outer cover41bby being cut in a U shape such that elastic plate41fis bent leftward and rightward according to the sliding of the holding member42; a hold protrusion part41gprotruding on a center of one surface of the elastic plate41fby having a cone shape such that the manipulation cover41is engaged with the holding member42so as to hold the holding member42at a position to which the holding member42slides; a rotation groove part41hbeing recessed in a lower end of one surface of each of the inner and outer covers41aand41bby being stepped in a semicircular shape, the rotation groove part41hbeing configured to restrict the rotating member43such that the rotating member43is rotatable; and a hold groove part41ibeing recessed in a lower end of one surface of each of the inner and outer covers41aand41bby being stepped in an arc shape, the hold groove part41ibeing configured to interfere with the rotating member43so as to limit a rotation range of the rotating member43.

Additionally, according to the present disclosure, the holding member42may include: a holding block42abeing mounted to a first side of an inside of the manipulation cover41so as to slide forward and backward, the holding block42abeing configured to be connected to the rotating member43so as to receive forward and backward movement force therefrom; a rear holder42bbeing mounted to a center of an upper end of the holding block42aso as to be rotated forward and backward, the rear holder42bbeing configured to press the rear cord32so as to slant the rear cord32downward according to backward movement of the holding block42asuch that the rear cord32is held to perform only downward movement; a front holder42cbeing mounted to the center of the upper end of the holding block42aso as to be rotated forward and backward, the front holder42cbeing configured to press the front cord31so as to slant the front cord31downward according to forward movement of the holding block42asuch that the front cord31is held to perform only downward movement; a compression spring42dprovided between the front and rear holders42cand42band configured to apply predetermined elastic force to each of the front and rear holders42cand42bsuch that each of the front and rear holders42cand42bis rotated outward; and a holding cover42ebeing mounted on a second side of the inside of the manipulation cover41so as to slide forward and backward, the holding cover42ecovering the holding block42aso as to prevent removal of each of the front and rear holders42cand42b.

In addition, according to the present disclosure, the holding block42amay include: a connection groove part42a-1being cut through a center of a lower end of the holding block42aby having a predetermined size such that the connection groove part42a-1is connected to the rotating member43so as to receive forward and backward movement force therefrom; a rotation pin42a-2inserted into and mounted to or protruding integrally from an upper end of a first surface of the holding block42asuch that the front and rear holders42cand42bare rotatably mounted on the rotation pin42a-2while overlapping each other; a cover groove part42a-3being recessed horizontally in the front-to-rear direction in a lower end of the first surface of the holding block42asuch that the holding block42aand the holding cover42etogether move forward and backward by being engaged with each other; older protrusion parts42a-4protruding on the upper end of the first surface of the holding block42aby having depths to receive the front and rear holders42cand42bsuch that the holder protrusion parts42a-4interfere with the front and rear holders42cand42bso as to limit outward rotating ranges thereof; a block rail groove part42a-5being recessed horizontally in the front-to-rear direction in a center of a second surface of the holding block42asuch that the holding block42aslides forward and backward by being engaged with the manipulation cover41; and holding groove parts42a-6being arranged in a lower end of the second surface of the holding block42aby being recessed at predetermined intervals therefrom such that the holding block42ais engaged with the manipulation cover41so as to be held at a position to which the holding block42aslides.

Furthermore, according to the present disclosure, the front and rear holders42cand42bmay include: holder rotation holes42b-1and42c-1formed respectively through centers of upper ends of the rear and front holders42band42cby having predetermined diameters, respectively, such that the front and rear holders42cand42bare mounted to an upper end of the holding block42aso as to be rotatable forward and backward directions; spring protrusion parts42b-2and42c-2protruding respectively on lower ends of surfaces of the rear and front holders42band42cfacing each other by having predetermined sizes, respectively, such that the spring protrusion parts42b-2and42c-2are inserted into the compression spring42dreceive outward rotating forces therefrom; and holder blades42b-3and42c-3respectively protruding slantingly on lower ends of the rear and front holders42band42cby having V shapes such that the holder blades42b-3and42c-3press the rear and front cords32and31by being in linear contact therewith so as to hold the rear and front cords32and31.

Additionally, according to the present disclosure, the holding cover42emay include: pin hole part42e-1being recessed in an upper end of a first surface of the holding cover42eby having a depth to receive the rotation pin42a-2such that each of the front and rear holders42cand42bis rotatably mounted on the rotation pin42a-2while overlapping each other; a cover protrusion part42e-2protruding on a lower end of the first surface of the holding cover42eby having a size to be engaged with the cover groove part42a-3such that the cover protrusion part42e-2is inserted into the cover groove part42a-3so as to move together with the cover groove part42a-3; and a cover rail groove part42e-3being recessed horizontally in the front-to-rear direction in a center of a second surface of the holding cover42esuch that the cover rail groove part42e-3is engaged with the manipulation cover41so as to slide the holding cover42eforward and backward.

In addition, according to the present disclosure, the rotating member43may include: a rotating body43ahaving an outer diameter to be mounted inside the manipulation cover41and having an inner diameter to receive the drive cord30; a rotation boss43bprotruding outward on each of upper and lower ends of the rotating body43aby having a predetermined diameter, the rotation boss43bbeing engaged with and holding the manipulation cover41such that the rotating member43is rotatable; a holding protrusion part43cprotruding on one side of an outer surface of the rotating body43aby having a predetermined size, the holding protrusion part43cbeing configured to interfere with the manipulation cover41such that a rotation range of the rotating body43ais limited; a connection boss43dprotruding on the lower end of the rotating body43aby having a predetermined shape, the connection boss43dbeing configured to be inserted into the manipulation tube44so as to receive the rotational force and the downward movement force from a user; and a crankshaft43eprotruding on one side of an upper end of the rotating body43aby having a predetermined length, the crankshaft43ebeing configured to be connected to the holding member42such that rotational movement is changed into forward/backward rectilinear movement so as to transmit the rectilinear movement to the holding member42.

Furthermore, according to the present disclosure, the manipulation tube44may include: an inner tube44awhich is mounted to a first side of the lower end of the rotating member43so as to cover the first side thereof and receives the front and rear cords31and32, the connecting member45, and the tension spring46; n outer tube44bwhich is mounted to a second side of the lower end of the rotating member43so as to cover the second side thereof and restricts the front and rear cords31and32, the connecting member45, and the tension spring46such that the front and rear cords31and32, the connecting member45, and the tension spring46are mounted in the inner tube44aby being covered by the outer tube44b; and a spring cap44cbeing inserted and mounted into a center portion between lower ends of the inner and outer tubes44aand44b, the spring cap44cbeing connected to a lower end of the tension spring46such that the drive cord30is held to be pulled.

First, according to the present disclosure, the drive cord including two drive cords is covered so as not to be seen from the outside, thereby preventing a dangerous situation in which the drive cord is wrapped around a person's body.

Second, according to the present disclosure, the holding member is moved by the rotating manipulation of the manipulation tube and holds any one drive cord of two drive cords, thereby lowering or raising the curtain fabric only by a simple manipulation of pulling the manipulation tube down.

Third, according to the present disclosure, the holder of the holding member holding the drive cord presses the drive cord such that the drive cord slants downward, so that the associated drive cord is securely held only when the drive cord is pulled downward, and the holding of the associated drive cord is automatically released when the drive cord is returned to a raised position, thereby lowering or raising the curtain fabric to a desired position only by repeating the pulling manipulation.

Fourth, according to the present disclosure, the tension spring allows the drive cord to be maintained in taut tension and allows the manipulation tube lowered by pulling to be automatically returned to a raised position, whereby the convenience of use is improved and a neat and tidy interior is created, thereby increasing satisfaction of a user overall.

In addition to the above-described effects, specific effects of the present disclosure will be described together while explaining specific details for carrying out the invention below.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the embodiment of the present document will be described with reference to the accompanying drawings. However, this is not intended to limit the technology described in this document to a specific embodiment, and it should be understood that various modifications, equivalents, and/or alternatives of the embodiment of this document are included. In connection with the description of the drawings, like reference numerals may be used for like components.

In addition, expressions such as “first” and “second” used in this document may modify various elements regardless of order and/or importance, and are used only to distinguish one element from another element but do not limit the corresponding components. For example, “first part” and “second part” may represent different parts regardless of order or importance. For example, without departing from the scope of the claims described in this document, the first component may be named as the second component, and similarly, the second component may also be named as the first component.

In addition, terms used in this document are used only to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meanings as commonly understood by those skilled in the art described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted to have the same or similar meaning as meaning in the context of the related art, and unless explicitly defined in this document, are not interpreted as deal or excessively formal meanings. In some cases, even terms defined in this document cannot be construed to exclude the embodiment of the present document.

The present disclosure relates to a roller blind drive device which lowers or raises a curtain fabric1by performing the forward/reverse rotation of a drum2on which a curtain fabric1is wound as illustrated inFIG.1. The present disclosure relates to a roller blind drive device preventing an accident due to a drive cord, the drive device having a fixed part10, a rotating part20, a drive cord30, and a manipulating part40as important components as illustrated inFIGS.2to4.

In this case, forward rotation mentioned in the present disclosure indicates the clockwise rotation of the drum2when the roller blind is seen from the right side relative toFIG.1.

That is, when the drum2is rotated in clockwise, the curtain fabric1wound on the drum2is lowered while being unwound, and when the drum2is rotated in counterclockwise, the curtain fabric1is raised while being wound on the drum2.

First, as illustrated inFIG.1, the fixed part10according to the present disclosure is fixedly disposed on the right or left side of the drum2and supports the drum2such that the drum2is rotatable.

As illustrated inFIGS.2to4, such a fixed part10is composed of a fixed casing11and a fixed shaft12.

The fixed casing11is formed in a disk shape having an inner diameter such that the fixed casing11can receive a rotating wheel21to be described later.

The fixed shaft12is inserted into and mounted to the center of the fixed casing11and supports the rotating wheel21such that the rotating wheel21is rotatable.

Here, the fixed casing11is configured to have an open path, which has a predetermined size, formed on a lower end thereof such that the drive cord30is connected to the rotating part20and the manipulating part40.

In this case, as illustrated inFIGS.5(a) and5(b), the fixed casing11includes a cord guide11aand a manipulation guide11bformed therein.

The cord guide11aprotrudes on each of the front and rear sides of the lower end of the fixed casing11by having a predetermined length, and guides the drive cord30connected to the rotating wheel21such that the drive cord30is connected to the manipulating part40by being in alignment therewith.

The manipulation guide11bis connected to and protrudes on one side of a guide protrusion part11ain a front-to-rear direction, and guides the return of the manipulating part40lowered by a user to an original position.

That is, the manipulation guide11binterferes with and arranges cover guides41cof a manipulation cover41raised by a tension spring46to be described later such that the manipulation cover41is returned to an original position.

Next, the rotating part20according to the present disclosure is mounted rotatably to the fixed part10as illustrated inFIG.1and allows the forward/reverse rotation of the drum2to be performed such that the curtain fabric1is lowered or raised.

As illustrated inFIGS.2to4, such a rotating part20is composed of the rotating wheel21and a drum holder22.

The rotating wheel21is rotatably mounted to the inner center of the fixed casing11, and receives forward/reverse rotational force transmitted by the drive cord30wound on the outer surface of the rotating wheel21.

The drum holder22is mounted to the rotating wheel21by being engaged therewith and is inserted into the center of one side of the drum2so as to perform the forward/reverse rotation of the drum2.

Next, as illustrated inFIGS.1to4, the drive cord30according to the present disclosure is connected to the rotating wheel21and a connecting member45in an infinite loop.

Such a drive cord30includes a front cord31and a rear cord32, each end of which is connected to each other, with the front cord31and the rear cord32being spaced apart from each other inside the fixed casing11located between the rotating wheel21and the connecting member45.

That is,FIGS.11(a),11(b),12(a), and12(b)are views illustrating the roller blind seen from the left side, and the front cord31is disposed at the right side, and the rear cord32is disposed at the left side.

Accordingly, when the front cord31is lowered, the rear cord32is raised, and at the same time, the rotating wheel21and the drive cord30are rotated clockwise.

Contrarily, when the rear cord32is lowered, the front cord31is raised, and at the same time, the rotating wheel21and the drive cord30are rotated counterclockwise.

Finally, as illustrated inFIGS.1and2, the manipulating part40according to the present disclosure is connected to the drive cord30hanging toward the lower side of the fixed casing11.

That is, the front cord31or the rear cord32according to the rotation and pulling manipulations of the manipulating part40by a user is selectively gripped to allow the forward/reverse rotation of the drive cord30to be performed.

As illustrated inFIGS.2to4, such a manipulating part40is composed of the manipulation cover41, a holding member42, a rotating member43, a manipulation tube44, the connecting member45, and the tension spring46.

The manipulation cover41is disposed to cover the drive cord30exposed to the lower side of the fixed part10, and receives the front and rear cords31and32such that the front and rear cords31and32are separated from each other in the front-to-rear direction and are moved upward and downward.

The holding member42is mounted to the center of the manipulation cover41so as to move slidably forward and backward, and presses and holds the front and rear cords31and32according to the forward and backward movements of the holding member42, respectively.

The rotating member43is rotatably mounted to the lower end of the manipulation cover41and is connected to the holding member42so as to move the holding member42forward or backward according to the rotation of the rotating member43.

The manipulation tube44is mounted to the lower end of the rotating member43and receives the drive cord30so as to receive the rotational force of the rotating member43and the downward movement force of the front and rear cords31and32from a user.

The connecting member45is mounted in the center of the manipulation tube44, and the drive cord30is connected to the upper end of the connecting member45.

The tension spring46is mounted to the center of the lower end of the manipulation tube44and is connected to the connecting member45so as to pull the connecting member45down.

That is, the tension spring46allows the drive cord30to be maintained in predetermined tension and allows the manipulation cover41to be returned to a raised position adjacent to the fixed part10.

In this case, the manipulation cover41is configured by being divided into an inner cover41aand an outer cover41b.

The inner cover41ais disposed on the left side of the lower part of the fixed casing11relative toFIG.3, and receives the front and rear cords31and32, the holding member42, and the rotating member43.

The outer cover41bis mounted to the right surface of the inner cover41aso as to cover the right surface thereof, and restricts the front and rear cords31and32, the holding member42, and the rotating member43such that the front and rear cords31and32, the holding member42, and the rotating member43are mounted in the inner cover41a.

As illustrated inFIGS.6and7, such a manipulation cover41includes the cover guides41c, separating protrusion parts41d, guide rails41e, an elastic plate41f, a hold protrusion part41g, a rotation groove part41h, and a hold groove part41i.

Each of the cover guides41cprotrudes on the upper end of each of the inner and outer covers41aand41b, and is guided to be returned to an original position by interfering with the manipulation guide11bdescribed above.

The separating protrusion parts41dprotrude on the upper and lower ends of the left surface of the inner cover41aby having predetermined lengths, and separate the front and rear cords31and32from each other such that the front and rear cords31and32can move upward and downward.

The guide rails41eprotrude on the centers of side surfaces of the inner and outer covers41aand41bfacing each other such that the guide rails41eare horizontal in the front-to-rear direction.

That is, each of the guide rails41esupports the holding member42to be described later such that the holding member42slides forward and backward.

The elastic plate41fprotrudes on the center of the outer cover41bby being cut in a U shape such that the elastic plate41fcan be bent leftward and rightward according to the sliding of the holding member42.

The hold protrusion part41gprotrudes on the center of the left surface of the elastic plate41fby having a cone shape, and is engaged with one of holding groove parts42a-6so as to hold the holding member42at a position to which the holding member42slides.

The rotation groove part41his recessed in the lower end of a side surface of each of the inner and outer covers41aand41bfacing each other by being stepped in a semicircular shape and restricts the rotating member43such that the rotating member43is rotatable.

The hold groove part41iis recessed in the lower end of a side surface of each of the inner and outer covers41aand41bfacing each other by being stepped in an arc shape, and limits the rotation range of the rotating member43.

In addition, as illustrated inFIGS.8to10, the holding member42includes a holding block42a, a rear holder42b, a front holder42c, a compression spring42d, and a holding cover42e.

The holding block42ais mounted to one side of the inside of the manipulation cover41so as to slide forward and backward, and is connected to a crankshaft43eto be described later so as to receive forward and backward movement force therefrom.

Such a holding block42aincludes a connection groove part42a-1, a rotation pin42a-2, a cover groove part42a-3, holder protrusion parts42a-4, a block rail groove part42a-5, and the holding groove parts42a-6.

The connection groove part42a-1is cut through the center of the lower end of the holding block42aby having a predetermined size, and receives the crankshaft43eby being engaged therewith so as to receive forward and backward movement force therefrom.

The rotation pin42a-2is inserted into and mounted to or protrudes integrally on the upper end of the left surface of the holding block42a, and supports the front and rear holders42cand42bsuch that the front and rear holders42cand42bcan rotate while overlapping each other.

The cover groove part42a-3is recessed horizontally in the front-to-rear direction in the lower end of the left surface of the holding block42a, and is connected to the holding cover42esuch that the holding block42aand the holding cover42etogether move forward and backward by being engaged with each other.

The holder protrusion parts42a-4protrude on the upper end of the left surface of the holding block42aby having depths to receive the front and rear holders42cand42b, and interfere with the front and rear holders42cand42bto limit outward rotating ranges thereof.

The block rail groove part42a-5is recessed horizontally in the front-to-rear direction in the center of the right surface of the holding block42a, and is engaged with the guide rail41esuch that the holding block42ais guided to slide forward and backward.

The holding groove parts42a-6are arranged in the lower end of the right surface of the holding block42aby being recessed at predetermined intervals therefrom, and induce the holding of the holding block42asuch that each of the holding groove parts42a-6is engaged with the hold protrusion part41gso as to allow the holding block42ato be held at a position to which the holding block42aslides.

The rear holder42band the front holder42care mounted to the rotation pin42a-2such that the rear holder42band the front holder42coverlap each other, and each of the rear holder42band the front holder42crotates forward and backward relative to the rotation pin42a-2.

That is, the rear holder42bpresses the rear cord32to slant the rear cord32downward according to forward and rearward movements of the holding block42asuch that the rear cord32is held to perform only downward movement.

In addition, the front holder42cpresses the front cord31to slant the front cord31downward according to forward and rearward movements of the holding block42asuch that the front cord31is held to perform only downward movement.

Such rear and front holders42band42crespectively include holder rotation holes42b-1and42c-1, spring protrusion parts42b-2and42c-2, and holder blades42b-3and42c-3.

The holder rotation holes42b-1and42c-1are formed respectively through the centers of the upper ends of the rear and front holders by having predetermined diameters and receive the rotation pin42a-2.

The spring protrusion parts42b-2and42c-2protrude on lower ends of surfaces facing each other by having predetermined sizes, respectively, and are inserted into the compression spring42dso as to receive outward rotating forces therefrom.

The holder blades42b-3and42c-3respectively protrude slantingly on lower ends of the rear and front holders42band42cby having V shapes, and press the rear and front cords32and31by being in linear contact therewith.

The compression spring42dis provided between the front and rear holders42cand42b, and applies predetermined elastic force to the front and rear holders42cand42bsuch that the front and rear holders42cand42bare opened in the front-to-rear direction.

The holding cover42eis mounted to the left surface of the holding block42aso as to cover the left surface of the holding block42aand restricts the front and rear holders42cand42bso as to prevent removal of each of the front and rear holders42cand42b.

Such a holding cover42eincludes a pin hole part42e-1, a cover protrusion part42e-2, and a cover rail groove part42e-3.

The pin hole part42e-1is recessed in the upper end of the right surface of the holding cover42eby having a predetermined depth and receives the rotation pin42a-2.

The cover protrusion part42e-2protrudes on the lower end of the right surface of the holding cover42eby having a predetermined size and is inserted into the cover groove part42a-3.

The cover rail groove part42e-3is recessed horizontally in the front-to-rear direction in the center of the left surface of the holding cover42eand is engaged with the guide rail41esuch that the holding cover42eis guided to slide forward and backward.

In addition, as illustrated in8and11, the rotating member43includes a rotating body43a, a rotation boss43b, a holding protrusion part43c, a connection boss43d, and the crankshaft43ewhich are integrated with each other.

The rotating body43ais configured to have a tube shape having an outer diameter to be mounted in the manipulation cover41and an inner diameter to receive the drive cord30.

The rotation boss43bprotrudes outward on each of the upper and lower ends of the rotating body43aby having a predetermined diameter. The rotation boss43bis engaged with each of the lower surface of the manipulation cover41and the rotation groove part41hand holds the rotating body43asuch that the rotating body43ais rotatable.

The holding protrusion part43cprotrudes on one side of the outer surface of the rotating body43aby having a predetermined size, and interferes with the hold groove part41isuch that the rotation range of the rotating body43ais limited.

The connection boss43dprotrudes on the lower end of the rotating body43aby having a predetermined shape, and is inserted into the manipulation tube44such that the connection boss43dreceives a rotational force and downward movement force from a user.

The crankshaft43eprotrudes on the right side of the upper end of the rotating body43aby having a predetermined length. The crankshaft43eis inserted into the connection groove part42a-1such that rotational movement is changed into forward/backward rectilinear movement so as to transmit the rectilinear movement to the holding block42a.

In addition, as illustrated inFIGS.3and4, the manipulation tube44includes an inner tube44a, an outer tube44b, and a spring cap44c.

The inner tube44ais mounted to a first side of the connection boss43dso as to cover the first side of the connection boss43d, and receives the front and rear cords31and32, the connecting member45, and the tension spring46in the inner tube44a.

The outer tube44bis mounted to a second side of the connection boss43dso as to cover the second side of the connection boss43d, and restricts the front and rear cords31and32, the connecting member45, and the tension spring46such that the front and rear cords31and32, the connecting member45, and the tension spring46are mounted in the inner tube44aby being covered by the outer tube44b.

The spring cap44cis inserted and mounted into a center portion between the lower ends of the inner and outer tubes44aand44b, and is connected to the lower end of the tension spring46such that the drive cord30is held to be pulled.

Hereinafter, the operation process of the drive device according to the present disclosure in which the curtain fabric1wound on the drum2is unwound and lowered will be described.

First, in order to lower the curtain fabric1, a user turns the manipulation tube44right as illustrated inFIG.11(b).

That is, when the rotating member43rotates right together with the manipulation tube44, the holding member42connected to the rotating member43is moved to the left side (backward).

When the holding member42is moved to the left side, the rear holder42bpresses the rear cord32and holds the rear cord32in the manipulation casing41.

In this state, when a user pulls the manipulation tube44down, the rear cord32is pulled down and the front cord31is moved upward as illustrated inFIG.12(a).

That is, together with the drive cord30, the rotating wheel21and the drum holder22are rotated counterclockwise relative to the drawing, and the curtain fabric1wound on the drum2is unwound and lowered as much as the rotating wheel21and the drum holder22are rotated counterclockwise.

Meanwhile, when a user pulls the manipulation tube44down, the tension spring46is stretched while the elastic energy of the tension spring46is accumulated as illustrated inFIG.13(a).

When the curtain fabric1is lowered to a desired position by pulling the manipulation tube44, a user releases the manipulation tube44which he or she pulls or slowly raises manipulation tube44.

That is, while the tension spring46is being contracted as illustrated inFIG.13(b)from a moment at which a user's pulling force is released, the manipulation tube44is returned to an initial position as illustrated inFIG.12(b).

Here, while the manipulation tube44and the manipulation casing41are raised, the rear holder42bis rotated toward the right side (the front) and slides on the rear cord32.

That is, while the curtain fabric1is held, the manipulation tube44is returned, and when the manipulation tube44is pulled down again, the curtain fabric1is lowered as much as the manipulation tube44is pulled.

Accordingly, a user can lower the curtain fabric1up to the bottom of the window only by repeating the manipulation of pulling the manipulation tube44.

For reference, the curtain fabric1is raised by pulling the manipulation tube44after turning the manipulation tube44leftward from the manipulation casing41.

In the above, the exemplary embodiment of the present disclosure has been illustrated and described, but the present disclosure is not limited to the specific embodiment described above. Various modifications of the embodiment may be made by those of ordinary skill in the technical field to which the invention belongs without departing from the gist of the present disclosure claimed in the claims. These modified embodiments should not be individually understood from the technical spirit or prospect of the present disclosure.