High-Performance Bathing Assistance Device Having Improved Safety and Convenience

The present invention relates to an infant bathing assistance device configured to support an infant during bathing so as to enable the infant to stay upright.

Generally, an infant aged 5 to 24 months cannot stand up alone or cannot stay upright for a long time. For example, when a guardian bathes an infant or washes away feces after defecation, the guardian needs to use one hand to constantly maintain the standing posture of the infant while using the other hand to operate a shower nozzle, leading to guardian inconvenience.

In order to address the above-described problems, there have been proposed various bathing assistance devices configured to support an infant during bathing so as to enable the infant to stay upright. As an example of the related art, there has been provided an infant bathing assistance device disclosed in Korean Patent Laid-Open Publication No. 10-2022-0131036. Hereinafter, a configuration of the infant bathing assistance device will be described in detail with reference to.

The bathing assistance device of the related art is formed of an upper body partconfigured to support an upper body of an infant so as to enable the infant to stay upright, a pair of armrestsformed on both sides of the upper body partand configured to support the arms of the infant such that the infant does not fall off the bathing assistance device, a lower body partformed on the lower side of the upper body partand configured to prevent the bathing assistance device from falling over, and a height adjustment partconfigured to adjust the height of the upper body partwith respect to the lower body part. In addition, the armrestsare rotated in inward and outward directions. In this case, rotational operation of the armrests is restricted such that the armrests are selectively rotated in the outward direction. Accordingly, since the armrestsare not rotated outwards without operation of a guardian, the infant may stably rely on the armrests.

However, when the armrestsof the conventional bathing assistance device are rotated inwards, strong impact noise is continuously generated from the armrests. Further, when the armrestsare rotated outwards, the guardian must exert considerable force to release rotational operation restriction of the armrests.

Specifically, in the bathing assistance device of the related art, the armrestsare rotated inwards to fit the physique of the infant and then need to be controlled so as to restrict outward movement thereof. To this end, an angle adjustment part including a pair of gears and a compression spring is employed as a means to perform the above-described operation of the armrests. However, in this case, unpleasant impact noise is continuously generated from the angle adjustment part. That is, as shown in, in the bathing assistance device of the related art, fixed teethare integrally formed on the upper body, and rotation teethconnected thereto are formed to be operated in conjunction with the armrests. Further, a compression springis installed in the axial direction of the rotation teethsuch that connection therebetween is selectively maintained according to the rotation direction of the rotation teeth. In this case, the armrestsare rotated horizontally, and the fixed teethand the rotation teeththat control rotation of the armrests perform relative reciprocating motion in the axial direction perpendicular to the rotation direction of the armrest. Accordingly, in order to control the rotation using the two teeth of the armrests, it is necessary to provide the compression springconfigured to push the two gears in the axial direction. Furthermore, due to the above-described structural limitations, there is a problem in that, when the armrestsare rotated in the inward direction, the rotation teethreciprocate in the axial direction, and the two teeth collide with each other due to the compression spring, leading to continuous generation of strong impact noise.

Particularly, for the safety of the infant, the armrestsshould not be rotated outwards without the operation of the guardian. In this case, when the infant leans on the armrests such that the weight of the infant is concentrated on the armrests in a direction in which the armrestsare rotated outwards, the strong compression springcapable of sufficiently maintaining the connection between the two teeth needs to be used. Accordingly, louder impact noise is generated. Additionally, since the impact noise is generated close to the ears of the infant, the infant may experience serious discomfort.

In addition, when the armrestsneed to be rotated outwards after bathing, the connection between the rotation teethand the fixed teethneeds to be released. Here, a source of force for the connection between the two teeth is elastic force of the compression spring. That is, since the strong compression springis used as described above, there is a problem in that larger force than the elastic force of the compression spring is required to release rotation restriction operation of the armrests.

In addition, the bathing assistance device of the related art has a serious problem in that, when the armrestsare rotated inwards, the skin of the infant is suctioned into a gap between the upper body partand the armrests, or the skin is compressed, bruising the infant. Specifically, as shown in, contact portions A of the upper body partand the armrestsare operated in conjunction with each other in the same manner as a compression roller. For example, when the armrestsare rotated inwards, an object in contact with the contact portions A is suctioned into a gap between the contact portions A by frictional force and are compressed. Accordingly, when the armrestsare rotated inwards in a state in which the skin of the infant is in contact with the contact portions A, the skin of the infant is suctioned into the gap therebetween by movement of the contact portions A. Furthermore, there is an additional problem in that, since the gap is formed to be significantly narrow, the skin of the infant is strongly compressed and is bruised, causing a serious degree of injury.

Meanwhile, in order to prevent, when the bathing assistance device is used for the infant, the infant from having difficulty in bathing or losing posture during bathing, a means to attract the interest of the infant may be additionally provided. In the related art, play means such as a display part and a soap bubble generating part are mounted on the bathing assistance device. However, the infant may not be interested in the above-mentioned play means for attracting the interest of the infant or the guardian may not prefer the play means. In this case, the conventional play means cannot be replaced with another one. Further, although the interest of the infant decreases due to repeated use of the conventional play means, the conventional play means cannot be replaced with a new one. In addition, since the above-mentioned play means are provided in a state of being mounted on the bathing assistance device, a user has no choice but to buy the play means even if the play means are not to be used, leading to a significant increase in purchase cost.

In addition, in order to attract the interest of infants aged 5 to 24 months who use the bathing assistance device, it is generally recommended to provide a means capable of attracting visual and tactile interest of the infants through a play process involving directly touching an object with the hands. However, the above-mentioned display part may have a harmful effect on infants aged 5 to 24 months, so the display part may not serve as a safe means capable of attracting the visual interest of infants. Additionally, in the case of the soap bubble generating part, since soap bubbles are generated from the armrestswhere the armpits are located, it is difficult to see and touch the soap bubbles directly. Further, since the soap bubbles may enter the infant's mouth, the soap bubble generating part may not be considered as a safe and effective means for attracting the interest of the infant.

Meanwhile, in the bathing assistance device of the related art, a drainage hole is formed only in a stepping plate located at a portion of the lower body partand configured to allow the infant to step thereon. In this case, since a gap formed between the floor of the bathroom or bathtub and the floor of the lower body partis very narrow, there is a problem in that foreign substances such as washing water or feces flowing into the stepping plate are not appropriately discharged. Additionally, a significant portion of the washing water and the like is discharged through the open rear side of the lower body part. Particularly, when the bathing assistance device is tilted forwards due to the slope of the floor of the bathroom or bathtub, there is a problem in that the washing water and the like are not discharged quickly through the drainage hole. In addition, since foreign substances such as feces are not quickly discharged, the foreign substances may move and come into contact with the infant's feet again inside the stepping plate, or even if the foreign substances are discharged through the drainage hole, the foreign substances remain on the floor of the bathroom or bathtub or the floor of the lower body partbecause the gap between the floor of the bathroom or bathtub and the floor of the lower body part is very narrow, resulting in a serious hygiene problem. Further, when washing water is accumulated on the floor, the infant may slip and fall due to the washing water, causing a safety incident.

In addition, since the bathing assistance device is used in the bathroom, the same is generally stored on the floor of the bathroom or bathtub. Here, the size of the bathing assistance device is considerable compared to a narrow bathroom area, causing inconvenience due to the space occupied by the bathing assistance device when the bathroom is used for other purposes. Additionally, there is a problem in that mold growth may occur due to moisture remaining on a portion of the bathing assistance device, which comes into contact with the bathroom floor, such as the floor of the lower body part. Meanwhile, the bathing assistance device is often used for other purposes. For example, the bathing assistance device is brought into a living room or a room from the bathroom and is used to support the infant when diapers or clothes are changed. In this case, when the bathing assistance device is stored on the floor of the bathroom or bathtub as described above, water on the floor of the lower body part and other parts may not dry well, causing inconvenience and hygiene problems due to water dripping on the floor of a living room or a room when the bathing assistance device is moved out of the bathroom.

Meanwhile, although the outward rotation of the armrests respectively disposed on both sides of the upper body part is restricted to prevent the infant from falling off the upper body part, when the infant's weight is excessively concentrated on the respective ends of the armrests, the flexible upper body of the infant may fall into a space between the respective ends of the armrests disposed on both sides of the upper body part, or the infant having undeveloped lower body muscles may fall down. At this time, the infant's neck may be moved out of the space between the respective ends of the armrests disposed on both sides of the upper body part, and then the infant may be moved out of the upper body part, leading to a slip and fall accident.

In addition, the armrests are hinged to the upper body part, and operating holes need to be formed to rotate the armrests. As shown in, since the armrests are formed in a horizontal structure, water flowing into the armrests through the respective operating holes is not naturally discharged to the outside. In some cases, the bathing assistance device needs to be tilted to drain the water, causing user inconvenience. In this case, water inside the armrests may be moved deeper inside the armrests. As described above, when water remains inside the armrests, a water flowing sound occurs inside the bathing assistance device, and a hygiene problem such as mold growth inside the bathing assistance device occurs.

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an infant bathing assistance device including a rotation control means formed in a different manner from a conventional control method relying on a strong compression spring vertically acting on the rotating plane of armrests, wherein the rotation control means is configured to restrict the rotation operation of both armrests provided in the bathing assistance device and configured to interact with each other on the same plane so as to use external force rotating the armrests as control force such that a powerful compression spring is not required, noise is reduced, and rotation restriction release operation is executable using small force, a skin protection means capable of preventing, when the armrests are rotated inwards, a skin of an infant from being suctioned or compressed into a gap between an upper body part and the armrests, wherein the skin is suctioned or compressed into the gap by operation of contact portions of the upper body part and the armrests, a play means attachable to or detachable from the bathing assistance device, wherein the play means is configured to be replaced with a safe play means preferred by the infant or a guardian, and the guardian is allowed to purchase only the bathing assistance device excluding the play means, a discharge hole and a discharge passage formed in a different manner from a conventional structure including a drainage hole only formed in a stepping plate, wherein the discharge hole and the discharge passage are forming in a boundary part located at the front or side of the stepping plate so as to quickly discharge, to the outside, foreign substances such as washing water and feces flowing into the stepping plate, an anti-slip pad detachably mounted on the upper portion of a lower body part, wherein the anti-slip pad is configured to prevent a slip and fall accident in which the infant slips and falls on the upper portion of the lower body part, a hanging means configured to enable the infant bathing assistance device to be stored in the bathroom in an easier manner for efficient use of a bathroom space than a conventional method in which the infant bathing assistance device is stored on the bathroom or bathtub floor such that the infant bathing assistance device is easy to dry and is used hygienically, separation prevention parts formed on the respective ends of the armrests, wherein a gap formed between the separation prevention parts is configured to be less thancm when the armrests are fully rotated inwards to reduce a space therebetween such that the neck of the infant, which is the thinnest part of the infant's upper body, is not allowed to pass through the gap, thereby preventing the infant from falling into the space between the ends of the armrests even if the weight of the infant is excessively concentrated on the ends of the armrests or an infant having underdeveloped lower body muscles falls, a partition wall configured to block water from flowing into the armrests so as to maximally reduce a water inflow section, and a drainage hole configured to discharge water introduced into the armrests to the outside, thereby preventing water from remaining inside the armrests and solving problems related to water noise and mold growth.

In accordance with the present invention, the above and other objects can be accomplished by the provision of an infant bathing assistance device configured to enable an infant to stay upright without falling when a guardian bathes the infant, the infant bathing assistance device including an upper body part configured to support an upper body of the infant, armrests each configured to support an arm portion or an armpit portion of the infant so as to enable the infant to stay upright, and a lower body part formed on a lower side of the upper body part, the lower body part being configured to support a lower body of the infant, wherein the armrests rotatably formed on the upper body part are rotated in an inward direction to reduce a space between the armrests or are rotated in an outward direction to increase the space therebetween, the infant bathing assistance device including a rotation control means configured to restrict rotation of the armrests in one of the inward and outward directions, wherein the rotation control means may include a fixed wheel, a rotating wheel, and a stopper interposed between the fixed wheel and the rotating wheel to perform a constricting action. The constricting action may be performed through a process of reducing a gap between pressing areas of the fixed wheel and the rotating wheel, a process of increasing a gap between two pressing areas of the stopper, or a process of simultaneously performing the two processes. The stopper may be in point contact, line contact, or surface contact with the fixed wheel and the rotating wheel. The stopper may be formed as a single body or may be formed of a plurality of components combined with each other. At least one of the pressing areas of the fixed wheel, the rotating wheel, and the stopper may have an uneven portion formed thereon. The infant bathing assistance device may further include a contact-maintaining means configured to enable the stopper to maintain contact with the fixed wheel and the rotating wheel. The contact-maintaining means may be an elastic body or a magnetic body. The rotation control means may include a positioning means configured to set an operating range of the stopper such that the stopper is moved within a predetermined range. The positioning means may be a side wall of a concave groove formed in the fixed wheel or the rotating wheel or a guide ring formed between the fixed wheel and the rotating wheel. Each of the armrests may have a rotation shaft provided therein, and each of the armrests and the rotation control means may be selectively operated in conjunction with each other depending on an axial position of the rotation shaft. A locking groove may be formed in a central portion of rotation of the rotating wheel, a locking protrusion may be partially formed on an outer circumferential surface of the rotation shaft, and the locking groove and the locking protrusion may be selectively coupled to each other depending on the axial position of the rotation shaft.

The infant bathing assistance device may include a skin protection means configured to prevent the skin of the infant from being caught in a gap between the upper body part and each of the armrests or to prevent the skin of the infant from being compressed even if the skin is located in the gap. The skin protection means may be a skin-catching prevention space part having a predetermined shape, the skin-catching prevention space part being formed on one or both of the armrests and the upper body part. The skin protection means may be a blocking member configured to block a part or all of the gap.

A discharge hole may be formed in a boundary part located at one or both of a front portion and a side portion of a stepping plate formed on the lower body part, and a discharge passage connected to the discharge hole may be formed in a bottom surface of the lower body part.

The infant bathing assistance device may have a play means detachably mounted thereon. The play means may be installed by a support means detachable from the infant bathing assistance device, and the support means may be detachable from the play means. The support means may be formed to have a rod shape or a table shape.

The infant bathing assistance device may have at least one hanging means formed therein and configured to enable the infant bathing assistance device to be hung and stored on an existing bathroom structure such as a towel rack or a towel shelf or a hanging member formed on a bathroom wall surface. The hanging means may be formed to have a groove shape or a ring shape.

The infant bathing assistance device may include an anti-slip pad configured to prevent the infant from slipping on an upper portion of the lower body part. The anti-slip pad may be formed of a flexible resin, and the anti-slip pad may be formed to have a shape corresponding to a shape of a stepping plate. The anti-slip pad may have a protrusion formed on an upper surface thereof. The anti-slip pad may have a concave groove formed in a bottom surface thereof. The infant bathing assistance device may include an attachable/detachable means configured for the anti-slip pad to be attachable to and detachable from the lower body part, and the attachable/detachable means may be a suction plate formed on a bottom surface of the anti-slip pad. The attachable/detachable means may be a fixing protrusion formed on a bottom surface of the anti-slip pad and a fixing groove formed in a stepping plate.

The infant bathing assistance device may include separation prevention parts formed at respective ends of the armrests, the separation prevention parts being configured to prevent the infant from falling into the space between the armrests. A gap between the separation prevention parts formed at the respective ends of the armrests may becm or less in a state in which the armrests respectively formed on both sides of the upper body part are fully rotated inwards to reduce the space therebetween.

Each of the armrests may include a blocking means configured to block water from flowing through an inside of each of the armrests or a discharge means configured to discharge the water introduced into each of the armrests. Partition walls may be used as the blocking means configured to block the water from flowing through the inside of each of the armrests. The discharge means configured to discharge the water introduced into each of the armrests may be a drainage hole formed in a bottom surface of each of the armrests, and the drainage hole may be formed in plural. The drainage hole may be formed at a lowest position in a space partitioned by a reinforcing rib.

The present invention provides an infant bathing assistance device including rotation control means configured to interact with each other on the same plane and to control rotation of armrests by using external force that rotates the armrests without using elasticity of a strong compression spring, thereby having an effect of reducing noise when the armrests are rotated, relieving rejection of an infant with respect to the infant bathing assistance device due to strong noise, and releasing rotation restriction of the armrests with small force.

In addition, the infant bathing assistance device according to the present invention may include a skin-catching prevention space part formed in a gap between a contact portion of the upper body part and a contact portion of each of the armrests and configured to, when the armrests are rotated inwards, prevent the skin of the infant from being suctioned into the gap. Even if a part of the skin of the infant is suctioned into the gap, the skin is not compressed enough to cause injury to the skin. Additionally, a blocking member is installed to fundamentally block the skin of the infant from being suctioned into the gap. As a result, since injury such as bruising is prevented, the infant bathing assistance device may be reliably used, and rejection of the infant with respect to the infant bathing assistance device may be relieved.

Additionally, the infant bathing assistance device according to the present invention includes a play means detachably mounted thereon. Accordingly, the play means may be efficiently replaced with a new play means preferred by an infant or a guardian. Further, since a bathing assistance device excluding the play means may be purchased depending on the consumer's choice, it is possible not only to reduce the purchase cost of the bathing assistance device, but also to choose a play means that is generally recommended for the age of the infant using the bathing assistance device and is capable of visually and tactually attracting the interest of the infant. As a result, the infants may play with the play means while seeing the play means with their eyes and touching the same with their hands during the use of the bathing assistance device. Additionally, since the infant is interested in the play means during bathing, brain development and small muscle development of the infant may be achieved by allowing the infant to see and touch the play means.

Furthermore, the infant bathing assistance device according to the present invention includes a discharge hole having a sufficient size, wherein the discharge hole is formed in a boundary part located at the front or side of a stepping plate so as to rapidly discharge, to the outside, washing water and foreign substances such as feces flowing into the stepping plate. Therefore, foreign substances such as feces do not move and come into contact with the infant's feet again inside the stepping plate, and since the foreign substances are discharged through a drainage hole in the stepping plate, the foreign substances do not remain on the floor of the bathroom or bathtub or on a lower body part, thereby having an effect of maximally reducing hygiene problems and preventing the infant from slipping due to accumulated washing water.

Additionally, the infant bathing assistance device according to the present invention is easily stored in the bathroom using a hanging means such that a bathroom space is efficiently used. Further, since the bathing assistance device is easy to dry, mold does not grow, and thus the bathing assistance device is used hygienically. In addition, the bathing assistance device may be brought into a living room or a room from the bathroom so as to be used for other purposes such as supporting an infant when diapers or clothes are changed. In this case, since water remaining on the bottom portion of the lower body part dries well, water does not drip into a living room or a room when the bathing assistance device is moved out of the bathroom, thereby preventing any user inconveniences or hygiene problems.

In addition, since a detachable anti-slip pad is formed on the upper portion of the lower body part, it is possible to prevent the infant from slipping on the lower body part due to accumulated washing water. Further, since the anti-slip pad is easily attached to and detached from the lower body part through an attachable/detachable means, the anti-slip pad is easy to wash, thereby having an effect of preventing residual water stains or mold growth.

Additionally, a gap formed between separation prevention parts formed at the respective ends of the armrests is configured to be less thancm when the armrests are fully rotated inwards to reduce a space therebetween. Accordingly, the neck of the infant, which is the thinnest part of the infant's upper body, is not allowed to pass through the gap, thereby having an effect of preventing the infant from falling into the space between the ends of the armrests even if the weight of the infant is excessively concentrated on the ends of the armrests or an infant having underdeveloped lower body muscles falls.

Furthermore, since the ends of partition walls respectively provided on the upper and lower sides of the inside of each of the armrests are formed to contact and overlap each other, it is possible to maximally reduce a water inflow section by fundamentally blocking water introduced into an operation hole in each of the armrests from flowing into another partitioned space. Additionally, even though each of the armrests is formed in a horizontal structure, water flowing into each of the armrests through the operating hole does not remain inside each of the armrests but is naturally discharged through the operation hole, thereby having an effect of maximally reducing user inconvenience due to sounds of water remaining inside the armrests and eliminating hygiene problems such as mold growth inside the armrests.

In an infant bathing assistance device according to the present invention, a pair of armrestsis formed on both sides of an upper body part, and a lower body partand a height adjustment partare formed on the lower side of the upper body part. Hereinafter, each configuration of the bathing assistance device according to a preferred embodiment of the present invention will be described in detail with reference to.

The upper body partof the bathing assistance device according to the present invention supports the upper body of an infant so as to enable the infant to stay upright, and a pair of armrestsrotatably hinged to both sides of the upper body partsupports both arms or armpits of the infant and prevents the infant from falling off the upper body part. In this case, the upper body partand the armrestsare preferably formed to have a soft curved shape because the same come into contact with the infant's body, and a material of the surface of the upper body part and the armrests may be selected from hard or soft materials. Further, the armrestsmay be rotatably moved inwards to reduce a space between the armrests and may be rotatably moved outwards to increase the space therebetween. Further, the bathing assistance device includes a rotation control meansconfigured to selectively rotate the armrests in at least one of the inward and outward directions of the armrests, and the rotation control means is formed to be operated in conjunction with the armrestsso as to restrict the operation of the armrests. Preferably, since the rotation control meansrestricts outward rotation of the armrests, the armrestsdisposed on both sides of the upper body part are not rotatably moved outwards when there is no user operation, and thus the infant may stably rely on the armrests. Further, the armrestsare rotatably moved inwards to adjust a widthwise gap between the armrestsdisposed on both sides of the upper body part. In this manner, the armrests may fit the infant's physique. Meanwhile, it is also possible to control outward rotation and inward rotation of the armrestsdepending on the user's preference or the like.

The configuration of the rotation control meanswill be described in more detail below. The rotation control meansoperated in conjunction with the armrestincludes a fixed wheelformed on each of both sides of the upper body part, a rotating wheellocated on the same plane with respect to the fixed wheeland operated in conjunction with the armrest, stoppers,, andeach interposed between the fixed wheeland the rotating wheeland configured to restrict and release relative rotation between the fixed wheeland the rotating wheel, and a positioning means configured to adjust a predetermined operating range of each of the stoppers,, and, thereby enabling each of the stopper,, andto be moved within the predetermined operating range. The rotation control means may further include a contact-maintaining means configured for each of the stoppers,, andto maintain contact with the fixed wheeland the rotating wheelin a direction in which the relative rotation is restricted.

The restriction of relative rotation is achieved through constricting action between the fixed wheel, the rotating wheel, and each of the stoppers,, andinterposed therebetween. More specifically, when the rotating wheelis rotated in a direction in which rotation of the rotating wheelrelative to the fixed wheelis restricted, a gap between pressing areas of the fixed wheeland the rotating wheeland pressing areas of each of the stoppers,, andis reduced. That is, through a process of reducing a gap between the pressing areas of the fixed wheeland the rotating wheel, a process of increasing a gap between two pressing areas of the stopper, or a process in which the above-mentioned two gap changes simultaneously occur, rotation of the rotating wheelrelative to the fixed wheelmay be restricted by the constricting action through which the two pressing areas of each of the stoppers,, andinterposed between the fixed wheeland the rotating wheelpress and contact the respective pressing areas of the fixed wheeland the rotating wheel.

Meanwhile, during the above-mentioned rotation restriction operation, when each of the stoppers,, andis spaced apart from the fixed wheeland the rotating wheelwithout contacting the same in a direction in which the restriction is performed, the constricting action is not immediately performed. Accordingly, the rotating wheelmay be partially rotated before the constricting action occurs, or in some cases, the constricting action may not be performed effectively. As a means for minimizing the above-described problem, it is desirable to provide a contact-maintaining means configured to enable each of the stoppers,, andto be in contact with the fixed wheeland the rotating wheelin the direction in which the restriction is performed.

In addition, an uneven portion may be formed on at least one of the pressing areas of the fixed wheel, the rotating wheel, and each of the stoppers,, and, thereby preventing, when the rotation restriction operation is performed, slippage of each of the stoppers,, andand stably performing the constricting action. The uneven portion may be a protrusion formed on one side of the pressing area or a combination of a protrusion and a groove respectively formed on and in both sides of the contact surface, and the shape thereof is not limited to a sawtooth shape, a triangular shape, a semicircular shape, a diagonal shape, a dot shape, and the like.

The rotation restriction operation may be released when the operating state is changed from the state in which the constricting action is performed. In detail, when the rotating wheelis rotated in a direction in which restriction of rotation of the rotating wheelrelative to the fixed wheelis released, a gap between the pressing areas of the fixed wheeland the rotating wheeland the pressing areas of the stopper is increased. That is, through a process of increasing a gap between the pressing areas of the fixed wheeland the rotating wheel, a process of reducing a gap between two pressing areas of the stopper, or a process in which the above-mentioned two gap changes simultaneously occur, two pressing areas of the stopper interposed between the fixed wheeland the rotating wheelare released from a state in which the two pressing areas are in pressure contact with the respective pressing areas of the fixed wheeland the rotating wheel. In this manner, restriction of rotation of the rotating wheelrelative to the fixed wheelis released.

Meanwhile, in order to enable each of the stoppers,, andto stably restrict rotation of the rotating wheelrelative to the fixed wheelor release the rotation restriction, an operating range of the stopper needs to be limited. In this case, the operating range of the stopper is limited to a certain range by a combination of the pressing areas of the fixed wheeland the rotating wheeland the positioning means.

Hereinafter, an embodiment of the rotation control meansaccording to the present invention will be described with reference to. The fixed wheelsof the rotation control meansare respectively formed on both sides of the upper body part. Here, the rotating wheeloperated in conjunction with the armrestis inserted into a central portion of the fixed wheel, at least one stopperis interposed between the fixed wheeland the rotating wheel, and at least one recessed groovein which the stopperis positioned is formed. The recessed groovemay be formed in the rotating wheelor may be formed in the fixed wheel, as shown in. Here, the recessed grooveaccording to the embodiment has an inclined surfacein which an inclined pressing area is located such that, depending on the rotational direction of relative rotation between the fixed wheeland the rotating wheel, a gap between the pressing areas respectively formed on the fixed wheeland the rotating wheelis reduced to perform the constricting action or is increased to be released from a state in which the constricting action is performed. Meanwhile, in addition to the inclined surface, the recessed groovehas a side wallformed as a positioning means to limit the operating range of the stopperto a predetermined range, and the operating range of the stopperis limited to a predetermined range by a combination of the side wall and the pressing areas of the fixed wheeland the rotating wheel.

Therefore, according to the embodiment, when the armrestis rotated in the direction in which rotation of the armrest is restricted, the rotating wheelis restricted by the fixed wheelby the constricting action of the fixed wheel, the rotating wheel, and the stopper, thereby restricting rotation of the rotating wheel relative to the fixed wheel. Here, as external force that rotates the armrestis increased, force restricting the armrestis also increased. Accordingly, rotation of the armrestmay be effectively controlled only using external force acting on the armrestwithout using a strong compression spring.

Meanwhile, the stopperof the rotation control meansaccording to the embodiment is not limited to the above-described shape. As shown in, the stopper may be formed as a ball that makes a point contact with another portion or may be formed as a cylindrical shape (not shown) that makes line contact with another portion. Alternatively, as shown in, the stopper may be formed as a polyhedron that makes surface contact with another portion.

In addition, preferably, the rotation control meansfurther forms an elastic bodyor a magnetic bodyserving as a contact-maintaining means configured to allow the stopperto maintain contact with the fixed wheeland the rotating wheelin the direction in which the rotation restriction is performed. Specifically, during the rotation restriction operation performed by the rotation control means, when the stopperis spaced apart from the fixed wheeland the rotating wheelwithout contacting the fixed wheel and the rotating wheel in the direction in which the rotation restriction is performed, the constricting action is not immediately performed. Accordingly, the rotating wheelmay be partially rotated before the constricting action occurs, or in some cases, the constricting action may not be performed effectively. In this case, as a contact-maintaining means to maximally reduce occurrence of the above-described problem, the elastic bodymay be formed to enable the stopperto maintain contact with the fixed wheeland the rotating wheel. Here, the elastic bodymay be formed to have a coil shape, as shown in, or may be formed to have a plate shape, as shown in. In addition, the elastic bodymay be formed on the fixed wheelor the rotating wheelin consideration of the position at which the recessed grooveis formed and may also be formed on the stopper. If necessary, the elastic body may also be formed to be integrated with the fixed wheel, the rotating wheel, or the stopper.

A description will be given as to an example of using the magnetic bodyserving as the contact-maintaining means with reference to. One of the pair of magnetic bodiesconstituting the contact-maintaining means is formed on the rotating wheelor the fixed wheel, and the other is formed on the stopper. In this manner, the stoppermay maintain contact with the fixed wheeland the rotating wheelby using attractive or repulsive force generated between the magnetic bodieson both sides.

Meanwhile, rotation of the armrestis not restricted by operation of the elastic bodyor the magnetic body. As described above, rotation of the armrestsis restricted by the constricting action using external force to rotate the armrests. Accordingly, elastic force of the elastic bodyand magnetic force of the magnetic bodymay be provided to such an extent that the stopperconstantly contacts the fixed wheeland the rotating wheel.

Additionally, in order to prevent slippage of the stopperand to perform more reliable constricting action, as shown in, an uneven portionmay be formed on at least one of the pressing areas of the fixed wheel, the rotating wheel, and the stopper. In this case, the uneven portionmay be a protrusion formed on one side of the pressing area or a combination of a protrusion and a groove formed on and in both sides of the contact surface. The shape of the uneven portion is not limited to a sawtooth shape, a triangular shape, a semicircular shape, a diagonal shape, a dot shape, and the like.

Another embodiment of the rotation control means will be described with reference to. The stopperprovided in the rotation control meansis an irregular roller that makes line contact with the fixed wheeland the rotating wheelIn this case, an inclined surfaceis formed on the outer circumferential surface of one or both sides of the stoppersuch that a gap between pressing areas corresponding to both side surfaces of the stopper gradually changes. Here, when the armrestsare rotated in a direction in which rotation of the armrests is restricted, the stopperis rotated in a direction in which the gap between the pressing areas on both side surfaces is increased, and rotation of the armrestsis restricted by constricting action allowing both pressing regions of the stopperto be in pressure contact with the respective pressing regions of the fixed wheeland the rotating wheel. Conversely, when the armrestsare rotated in a direction in which rotation restriction of the armrests is released, the stopperis rotated in a direction in which the gap between the pressing areas on both side surfaces is reduced, and the armrestsare freely rotatable by escaping from the state in which the constricting action is performed.

Meanwhile, a positioning means needs to be formed to operate the stopperwithin a predetermined range. As shown in, a separate guide ringinto which at least one stopperis inserted is used, or as shown in, a recessed grooveis formed in the fixed wheelor the rotating wheelsuch that a side wallis used. In this manner, an operating range of the stopperis limited to a predetermined range by a combination of the positioning means and the respective pressing areas of the fixed wheeland the rotating wheel.

In addition, it is desirable to form the elastic bodyas a contact-maintaining means configured to enable the stopperto maintain contact with the fixed wheeland the rotating wheel. For example, as shown in, the elastic body may be installed on the stopperand may be selectively formed on any one of the fixed wheel, the rotating wheel, and the guide ring.