Bed

Abstract

According to one aspect of the present invention, provided is a bed comprising: a main frame; a bed frame comprising a sub-frame provided to be rotatable relatively to the main frame such that the sub-frame is placed in a first state in which a central portion of the sub-frame is disposed above the main frame to overlap the main frame or in a second state in which the central portion is disposed further forward than in the first state; a main link rotatably connected to the main frame and the sub-frame and rotated in the front-rear direction with respect to the main frame when the sub-frame is rotated such that the sub-frame is placed in any one of the second state and the first state; and a sub-link connected to the main frame and the sub-frame so as to be rotatable in front of the main link, and rotated in the front-rear direction with respect to the main frame when the sub-frame is rotated such that the sub-frame is placed in any one of the second state and the first state.

Description

bed

[0001] The present invention relates to a bed.

[0002] Typically, beds can be provided as standard beds on which the user can lie down, or as folding beds that can be converted to fold. Folding beds can be moved by rotating the leg rests that support the user's legs forward and backward, or by sliding them forward and backward.

[0003] Meanwhile, massage devices provide physical stimulation or pressure to the entire body or specific areas, promoting blood circulation and facilitating metabolism. Furthermore, massage devices apply pressure to muscles, relieving tension and thus relieving physical and mental fatigue, and contributing to fatigue recovery, disease prevention, and beauty. Conventional massage beds, which incorporate massage devices to massage the user while they lie or sit, have also been available.

[0004] In this regard, applicant Jeong Chan-in's Korean Patent Publication No. 10-2003-0087599, "Multifunctional bed with massage device" (Patent Document 1), discloses a bed equipped with a massage device so that a user can receive a massage function while lying down.

[0005] However, the multifunctional bed with a massage device of Patent Document 1 is composed of a single frame, so the bed must always be unfolded. In other words, the multifunctional bed of Patent Document 1 remains unfolded not only when the user is using the massage device, but also when the massage device is not in use. In this case, the multifunctional bed is always unfolded, even when the user is not using the massage device, resulting in a significant space-consuming problem.

[0006] Korean Patent Publication No. 10-1206967 "Sliding type thermal therapy device" (Patent Document 2) of the applicant, Seragem Co., Ltd., discloses a thermal therapy device that provides a treatment function to a user and a lower bed member that can slide relative to the body to cover the thermal therapy device.

[0007] However, since the lower bed member of the thermal therapy device of Patent Document 2 slides horizontally along a guide groove formed in the body, friction occurs as the lower bed member moves. In other words, there is a problem that friction occurs between the lower bed member and the body while the lower bed member slides, which may damage the lower bed member. In addition, since the lower bed member of the thermal therapy device of Patent Document 2 may rub against the body when moved by the user, there is a problem that a lot of force is required by the user to move the lower bed member.

[0008] (Prior art literature)

[0009] (Patent Document 1) Korean Patent Publication No. 10-2003-0087599 (Published on November 14, 2003)

[0010] (Patent Document 2) Korean Patent Publication No. 10-2012-0118398 (Published on October 26, 2012)

[0011] One embodiment of the present invention aims to provide a bed capable of reducing damage to a subframe by reducing the moving speed of the subframe when the subframe constituting the bedframe moves relative to the main frame.

[0012] According to one aspect of the present invention, a bed comprises: a bed frame comprising: a main frame; and a subframe provided to be rotatable relative to the main frame so as to be in a first state in which a center portion thereof is disposed above the main frame so as to overlap the main frame, or in a second state in which the center portion thereof is disposed further forward than the first state; a main link rotatably connected to the main frame and the subframe, and which rotates forward and backward relative to the main frame when the subframe is rotated so that the subframe is in either the second state or the first state; a sublink rotatably connected to the main frame and the subframe in a forward direction than the main link, and which rotates forward and backward relative to the main frame when the subframe is rotated so that the subframe is in either the second state or the first state; And, the main frame and the main link further include an elastic member rotatably connected to the main link so that the rotation center is arranged higher than the rotation center of the main link and the rotation center of the sub link, and the sub link includes a sub link bending portion having a curved shape, and the sub link bending portion is arranged at the upper portion of the front side of the main frame when the sub frame is in the second state, and is arranged at the lower portion of the main frame when the sub frame is in the first state, and the elastic member applies an elastic force in the direction in which the sub frame rises when the sub frame is rotated to rise or fall.

[0013] In addition, each of the sub-link and the main link rotates around different rotation axes extending in the left and right directions, and the elastic member can rotate in the opposite direction to the sub-link and the main link.

[0014] In addition, the sub-link includes a first sub-link end rotatably connected to the main frame, and a second sub-link end rotatably connected to the sub-frame from above the first sub-link end, and when the sub-frame rotates, the sub-link rotates around the first sub-link end, and the main link includes a first main link end rotatably connected to the main frame, and a first main link end rotatably connected to the sub-frame from above the first main link end, and when the sub-frame rotates, the sub-link rotates around the first main link end, and the elastic member includes a first elastic member end rotatably connected to the main frame, and a second elastic member end rotatably connected to the main link from below the first elastic member end, and when the sub-frame rotates, the sub-link rotates around the first elastic member end, and the first elastic member end may be disposed above the first sub-link end and the first main link end.

[0015] In addition, the main link may include a lower main link portion rotatably connected to the main frame; an upper main link portion rotatably connected to the subframe; and a main link bending portion connected between the lower main link portion and the upper main link portion so that the lower main link portion and the upper main link portion are misaligned with each other, and having a curved shape, and is disposed on the upper front side of the main frame when the subframe is in the second state, and is disposed on the lower side of the main frame when the subframe is in the first state.

[0016] In addition, the lower main link portion may be arranged so that the upper side thereof is inclined forward so as to form a first angle with respect to a virtual line extending in a vertical direction when the subframe is in the second state, and the upper main link portion may be arranged so that the upper side thereof is inclined forward so as to form a second angle smaller than the first angle with respect to the virtual line when the subframe is in the second state.

[0017] In addition, the sub-link further includes a lower sub-link portion rotatably connected to the main frame; and an upper sub-link portion rotatably connected to the sub-frame, and the sub-link bending portion is connected between the lower sub-link portion and the upper sub-link portion so that the lower sub-link portion and the upper sub-link portion are arranged to be misaligned with each other, and the lower sub-link portion is arranged so that the upper side thereof is inclined forward to form a third angle smaller than the second angle with respect to the virtual line when the sub-frame is in the second state, and the upper sub-link portion can be arranged parallel to the horizontal direction when the sub-frame is in the second state.

[0018] Additionally, the elastic member may be oriented in a direction corresponding to the extension direction of at least a portion of the main link when the subframe is rotated and the subframe is spaced a predetermined distance from the upper side of the main frame.

[0019] Additionally, the subframe may further include a damper that contracts when the subframe is rotated and rises, and extends when the subframe is lowered, thereby reducing the rotational speed of the subframe.

[0020] Additionally, the damper is disposed on the inside of the elastic member and can rotate together with the elastic member.

[0021] In addition, the main link and the main frame are supported, and a damper is further included that rotates in the forward and backward direction with respect to the main frame so as to extend when the subframe is rotated and raised, and contract when the subframe is lowered, thereby reducing the rotational speed of the subframe, and the center of rotation of the damper may be positioned lower than the main link and the sublink.

[0022] In addition, the main link includes a first main link end rotatably connected to the main frame, and a second main link end rotatably connected to the subframe above the first main link end, and when the subframe rotates, the main link rotates around the first main link end, the sublink includes a first sublink end rotatably connected to the main frame, and a second sublink end rotatably connected to the subframe above the first sublink end, and when the subframe rotates, the main link rotates around the first sublink end, and the damper includes a first damper end rotatably connected to the main frame, and a second damper end rotatably connected to the main link above the first damper end, and when the subframe rotates, the main link rotates around the first damper end, and the first damper end may be disposed below the first sublink end and the first main link end.

[0023] In addition, the elastic member includes a first elastic member end portion rotatably connected to the main frame, and a second elastic member end portion rotatably connected to the main link at a lower side than the first elastic member end portion, and when the subframe rotates, the elastic member rotates around the first elastic member end portion, and the second damper end portion may be disposed forward of the second elastic member end portion when the subframe is in the second state, and may be disposed rearward of the second elastic member end portion when the subframe is in the first state.

[0024] Additionally, the main link may be arranged between the elastic member and the damper in the left-right direction.

[0025] Additionally, the damper may be oriented in a direction corresponding to an extension direction of at least a portion of the main link when the subframe is rotated and the subframe is spaced a predetermined distance from the upper side of the main frame.

[0026] According to one aspect of the present invention, the elastic member can apply elastic force in the direction in which the subframe rises when the sub-link rotates to rise or fall, so that when the sub-frame rotates, the load on the sub-frame can be reduced and the moving speed of the sub-frame can be reduced.

[0027] In addition, the elastic member can provide elastic force when the subframe is moved from the first state or the second state at the beginning of the movement, thereby reducing the load when the subframe is moved, so that the user's force for moving the subframe can be reduced.

[0028] Additionally, the damper can contract or expand when the subframe moves, thereby reducing the load on the subframe and reducing the lowering speed of the subframe.

[0029] FIG. 1 is a perspective view showing a subframe of a bed according to a first embodiment of the present invention in a first state.

[0030] Figure 2 is an enlarged view of part A of Figure 1.

[0031] Figure 3 is a side view of the bed of Figure 1.

[0032] FIG. 4 is a perspective view showing a subframe of a bed according to a first embodiment of the present invention rotated so that the subframe faces the first state or the second state.

[0033] Figure 5 is a side view of the bed of Figure 4.

[0034] FIG. 6 is a perspective view showing the subframe of the bed according to the first embodiment of the present invention in a second state.

[0035] Figure 7 is a side view of the bed of Figure 6.

[0036] FIG. 8 is a side view showing the subframe of the bed according to the second embodiment of the present invention in the first state.

[0037] Figure 9 is a side view of the bed of Figure 8.

[0038] FIG. 10 is a side view showing the subframe of the bed according to the second embodiment of the present invention rotated so that the subframe faces the first state or the second state.

[0039] Fig. 11 is a side view of the bed of Fig. 10.

[0040] Fig. 12 is a side view showing the subframe of the bed according to the second embodiment of the present invention in a second state.

[0041] Figure 13 is a side view of the bed of Figure 12.

[0042] Hereinafter, specific embodiments for implementing the technical idea of ​​the present invention will be described in detail with reference to the drawings.

[0043] In addition, when explaining the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0044] Additionally, when it is said that a component is 'connected' or 'supported' by another component, it should be understood that it may be directly connected or supported by that other component, but there may also be other components in between.

[0045] The terminology used herein is intended solely to describe specific embodiments and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0046] Additionally, please note that the terms "upper side," "lower side," and "side" in this specification are based on the illustrations in the drawings and may be expressed differently if the orientation of the subject changes. For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted, and the sizes of each component do not fully reflect the actual size.

[0047] Additionally, terms that include ordinal numbers, such as "first," "second," etc., may be used to describe various components, but these components are not limited by such terms. These terms are used solely to distinguish one component from another.

[0048] The term "comprising" as used in the specification means specifying a particular characteristic, region, integer, step, operation, element and / or component, but does not exclude the presence or addition of other particular characteristics, regions, integers, steps, operations, elements, components and / or groups.

[0049] Hereinafter, a bed (1) according to the first embodiment of the present invention will be described.

[0050] Referring to FIGS. 1 to 3, a bed (1) according to a first embodiment of the present invention may be provided as a folding bed that can be converted to be folded. Such a bed (1) may include a main body (100), a bed frame (200), a main link (300), a sub link (400), an elastic member (500), and a damper (600).

[0051] The main body (100) can support a bed frame (200). The main body (100) can include an upper mattress on which the user's upper body can lie and a lower mattress on which the user's legs can be placed. A massage module that can massage the user by applying pressure to a body part of the user can be placed on the main body (100).

[0052] Referring further to FIGS. 4 to 7, the bed frame (200) can support the upper mattress and lower bed frame of the main body (100). In addition, the bed frame (200) can support a massage module. In addition, the bed frame (200) can include a main frame (210) and a subframe (220).

[0053] The main frame (210) can support the upper mattress of the main body (100) that can support the user's upper body. The main frame (210) can be connected to the subframe (220) via the main link (300) and the sub link (400). The first main link end (300a) of the main link (300) and the first sub link end (400a) of the sub link (400) can be rotatably connected to the lower part of the main frame (210).

[0054] The subframe (220) may be provided to be relatively movable with respect to the mainframe (210). For example, when the subframe (220) is moved by the rotation of the main link (300) and the sublink (400), the subframe (220) may be placed in a first state or a second state. The first state may be a state in which the center of the subframe (220) is positioned above the mainframe (210) so as to overlap with the mainframe (210). The second state may be a state in which the center of the subframe (220) is positioned further forward than in the first state. These first and second states may be referred to as an overlapping state and an extended state, respectively.

[0055] The main link (300) can movably connect the subframe (220) to the mainframe (210). The main link (300) can be rotatably connected to the mainframe (210) and the subframe (220). In other words, the first main link end (300a) of the main link (300) is rotatably connected to the mainframe (210), and the second main link end (300b) of the main link (300) can be rotatably connected to the subframe (220). The main link (300) can be rotated about the first main link end (300a) when the subframe (220) is rotated. The main link (300) can be bent to form a predetermined angle that is greater than a right angle and less than a flat angle. A main link (300) may be provided in multiple pieces, and the multiple main links (300) may be arranged on the left and right sides of the main frame (210). The main link (300) may include a lower main link portion (310), an upper main link portion (320), and a main link bending portion (330).

[0056] The lower main link part (310) can be rotatably connected to the main frame (210). An end of the lower main link part (310) can be a first main link end part (300a) rotatably connected to the main frame (210). The lower main link part (310) can extend in a different direction from the upper main link part (320). The lower main link part (310) can have a longer length than the upper main link part (320), the lower sub-link part (410) to be described later, and the upper sub-link part (420) to be described later. The lower sub-link part (410) can be connected to the upper sub-link part (420) so as to form a predetermined angle with each other. For example, the lower main link portion (310) may be arranged with its upper side tilted forward so as to form a predetermined first angle with a virtual line extending in the vertical direction when the subframe (220) is placed in the second state.

[0057] The upper main link part (320) may be rotatably connected to the subframe (220). An end of the upper main link part (320) may be a second main link end part (300b) rotatably connected to the subframe (220). The upper main link part (320) may extend in a different direction from the lower main link part (310). The upper main link part (320) may be connected to the lower main link part (310) to form a predetermined angle that is greater than a right angle and less than a flat angle. The upper main link part (320) may be arranged so that its upper side is inclined forward so as to form a second angle that is smaller than a first angle with respect to an imaginary line when the subframe (220) is placed in a second state.

[0058] The main link bending part (330) can connect the lower main link part (310) and the upper main link part (320). The main link bending part (330) can have a curved shape. The main link bending part (330) can be bent and connected between the lower main link part (310) and the upper main link part (320) so that the lower main link part (310) and the upper main link part (320) are arranged to be misaligned with each other. When the subframe (220) is placed in the second state, the main link bending part (330) can be arranged on the upper part of the main frame (210), and when the subframe (220) is placed in the first state, the main link bending part (330) can be arranged on the upper part of the main frame (210). In the drawing according to the present embodiment, the main link bending portion (330) is illustrated, but the main link bending portion (330) may be omitted. In other words, the lower main link portion (310) and the upper main link portion (320) may be directly connected to form a corner.

[0059] The sub-link (400) can movably connect the sub-frame (220) to the main frame (210). In addition, the sub-link (400) can be rotatably connected to the main frame (210) and the sub-frame (220) so as to be positioned forward of the main link (300). The first sub-link end (400a) of the sub-link (400) can be rotatably connected to the main frame (210), and the second sub-link end (400b) of the sub-link (400) can be rotatably connected to the sub-frame (220). The sub-link (400) can be rotated about the first sub-link end (400a) when the sub-frame (220) is rotated. The sub-link (400) can have a shape that is bent at a predetermined angle that is greater than a right angle and less than a straight angle. A plurality of sub-links (400) may be provided, and the plurality of sub-links (400) may be arranged on the left and right sides of the main frame (210). The sub-link (400) may include a lower sub-link portion (410), a sub-link bending portion (430), and an upper sub-link portion (420).

[0060] The lower sub-link unit (410) can be rotatably connected to the main frame (210). The lower sub-link unit (410) can extend in a different direction from the upper sub-link unit (420). The lower sub-link unit (410) can be connected to the upper sub-link unit (420) to form a predetermined angle with respect to each other. For example, the lower sub-link unit (410) can be connected to the upper sub-link unit (420) in the forward-rear direction through the sub-link bending unit (430) so that the angle formed with the upper sub-link unit (420) is less than a parallel angle and greater than a right angle. The lower sub-link unit (410) can extend forward when the sub-frame (220) is placed in the second state. The lower sub-link portion (410) may be arranged with its upper side tilted forward so as to form a third angle smaller than the first and second angles formed with a virtual line extending in the vertical direction when the sub-frame (220) is placed in the second state.

[0061] The upper sub-link portion (420) can be rotatably connected to the sub-frame (220). The upper sub-link portion (420) can extend in a different direction from the lower sub-link portion (410). The upper sub-link portion (420) can be connected to the lower sub-link portion (410) through the sub-link bend portion (430) so as to form an angle that is less than a straight angle and greater than a right angle. The upper sub-link portion (420) can be arranged parallel to the horizontal direction when the sub-frame (220) is in the second state.

[0062] The sub-link bending part (430) can be connected to the lower sub-link part (410) and the upper sub-link part (420). The sub-link bending part (430) can have a curved shape with a curvature. The sub-link bending part (430) can be bent and connected between the lower sub-link part (410) and the upper sub-link part (420). When the sub-frame (220) is placed in the second state, the sub-link bending part (430) can be placed on the upper side of the main frame (210), and when the sub-frame (220) is placed in the first state, the sub-link bending part (430) can be placed on the lower side of the main frame (210). Although the sub-link bending part (430) is illustrated in the drawing according to the present embodiment, the sub-link bending part (430) may be omitted. In other words, it is also possible for the lower sub-link portion (410) and the upper sub-link portion (420) to form a corner and be directly connected.

[0063] The elastic member (500) can be coupled to the main link (300) and the main frame (210) to apply elastic force to the main link (300). The elastic member (500) can be rotated by the rotation of the subframe (220). This elastic member (500) can apply elastic force in the direction in which the subframe (220) rises when the subframe (220) rotates and rises or falls. The elastic member (500) can be arranged such that one end is rotatably connected to the main link (300) and the other end is rotatably connected to the main frame (210), and one end is positioned higher than the other end. In other words, the elastic member (500) may include a first elastic member end portion (500a) rotatably connected to the main frame (210) and a second elastic member end portion (500b) rotatably connected to the main link (300) below the first elastic member end portion (500a). In addition, the elastic member (500) may be rotated about the first elastic member end portion (500a) when the subframe (220) is rotated. The elastic member (500), the main link (300), and the sub link (400) may be rotated about different rotation axes extending in the left and right directions. The center of rotation of the elastic member (500) may be rotatably connected to the main frame (210) and the main link (300) so as to be disposed above the center of rotation of the main link (300) and the center of rotation of the sub link (400). In other words, the first elastic member end portion (500a) of the elastic member (500) may be positioned above the sub-link end portion (400a) and the main link end portion (300a). When the elastic member (500) rotates, it may rotate in the opposite direction to the main link (300) and the sub-link (400).

[0064] The first elastic member end portion (500a) may be positioned above the first sub-link end portion (400a) and the second main link end portion (300a). In other words, the center of rotation of the elastic member (500) may be positioned above the center of rotation of the main link (300) and the center of rotation of the sub-link (400). When in the first state, the first elastic member end portion (500a) may be positioned rearward relative to the second elastic member end portion (500b). When in the second state, the first elastic member end portion (500a) may be positioned forward relative to the second elastic member end portion (500b).

[0065] In addition, the elastic member (500) can be oriented in a direction corresponding to the extension direction of at least a portion of the main link (300) when the subframe (220) is rotated and spaced apart from the upper side of the main frame (210) by a predetermined distance. In other words, the elastic member (500) can be covered by the main link (300) when the bed (1) is viewed from the side when the subframe (220) is rotated and spaced apart from the upper side of the main frame (210) by a predetermined distance.

[0066] The damper (600) can contract when the subframe (220) rotates and rises, and can extend when the subframe (220) descends, thereby reducing the rotational speed of the subframe (220). In other words, the damper (600) can be a gravity compensation device that contracts when the subframe (220) rises and reduces the load of the subframe (220). For example, the damper (600) can be an oil damper. This damper (600) can be arranged inside the elastic member (500) and can extend, contract, and rotate together with the elastic member (500). In other words, the damper (600) can be formed integrally with the elastic member (500).

[0067] Hereinafter, the operation and effect according to the first embodiment of the present invention will be described.

[0068] The elastic member (500) of the bed (1) according to the first embodiment of the present invention can apply elastic force in the direction in which the sub-frame (220) rises when the sub-link (400) rotates to rise or fall, so that when the sub-frame (220) rotates, the load can be reduced and the moving speed of the sub-frame (220) can be reduced.

[0069] In addition, the damper (600) can contract when the subframe (220) moves and rises, and can extend when the subframe (220) descends, so that when the subframe (220) rotates, the load on the subframe (220) can be reduced and the moving speed of the subframe (220) can be reduced.

[0070] Hereinafter, a bed (1) according to a second embodiment of the present invention will be described with reference to FIGS. 8 to 13. In describing the second embodiment, there is a difference in that the damper (600) is supported on the main link (300) and the main frame (210), and this difference will be primarily described.

[0071] The damper (600) may be supported by the main link (300) and the main frame (210) so as to rotate in the front-back direction with respect to the main frame (210). In other words, the damper (600) may include a first damper end (600a) that is rotatably connected to the main frame (210) and a second damper end (600b) that is rotatably connected to the main link (300) above the first damper end (600b). The damper (600) may be arranged so as to extend when the subframe (220) rotates upward and contract when the subframe (220) rotates downward, thereby reducing the rotational speed of the subframe (220). The center of rotation of the damper (600) may be arranged lower than the centers of rotation of the main link (300) and the sublink (400). In other words, the damper (600) can be rotated around the first damper end (600a). In addition, the first damper end (600a) can be positioned lower than the first sub-link end (400a) and the first main link end (300a).

[0072] When the subframe (220) is in the second state, the second damper end portion (600b) may be positioned forward of the second elastic member end portion (500b), and when the subframe (220) is in the first state, the second damper end portion (600b) may be positioned rearward of the second elastic member end portion (500b). By means of the damper (600), the main link (300) may be positioned between the elastic member (500) and the damper (600) in the left-right direction.

[0073] Additionally, the damper (600) may be oriented in a direction corresponding to the extension direction of at least a portion of the main link (300) when the subframe (220) is rotated and the subframe (220) is spaced apart from the upper side of the main frame (210) by a predetermined distance. In other words, when the subframe (220) is rotated and the subframe (220) is spaced apart from the upper side of the main frame (210) by a predetermined distance, the damper (600) may cover a portion of the main frame (210) when viewed from the side.

[0074] Hereinafter, the operation and effect of the bed (1) according to the second embodiment of the present invention will be described.

[0075] The damper (600) of the bed (1) according to the second embodiment of the present invention can reduce the moving speed of the subframe (220) by contracting when the subframe (220) is lowered, so that the lowering speed of the subframe (220) can be reduced.

[0076] Although specific embodiments of the present invention have been described, these are merely examples, and the present invention is not limited thereto, but should be construed to have the broadest scope consistent with the technical concepts disclosed herein. Those skilled in the art may combine / substitute the disclosed embodiments to implement patterns of shapes not specified, but this also does not depart from the scope of the present invention. In addition, those skilled in the art may easily modify or alter the disclosed embodiments based on the present specification, and it is clear that such modifications and alterations also fall within the scope of the present invention.

Claims

1. A bed frame including a main frame; and a subframe that is provided to be rotatable relative to the main frame so that the central portion thereof is positioned on the upper side of the main frame so as to overlap the main frame in a first state, or is positioned further forward than the first state in a second state; A main link rotatably connected to the main frame and the subframe, and rotated in the forward and backward direction with respect to the main frame when the subframe is rotated so that the subframe is placed in one of the second state and the first state; A sub-link rotatably connected to the main frame and the sub-frame in front of the main link, and when the sub-frame is rotated so that the sub-frame is placed in one of the second state and the first state, the sub-link rotates forward and backward with respect to the main frame; and It includes an elastic member rotatably connected to the main frame and the main link so that the center of rotation is positioned higher than the center of rotation of the main link and the center of rotation of the sub link, The above sub-link includes a sub-link bending portion having a curved shape, The above sub-link bending part is, When the subframe is in the second state, it is placed on the upper front side of the main frame, and when the subframe is in the first state, it is placed on the lower side of the main frame. The above elastic member is, When the above subframe rotates and rises or falls, elastic force is applied in the direction in which the above subframe rises. Bed.

2. In paragraph 1, Each of the above sub-link and the above main link rotates around different rotation axes extending in the left and right directions, The above elastic member rotates in the opposite direction to the sub-link and the main link. Bed.

3. In paragraph 1, The above sublink is, It includes a first sub-link end rotatably connected to the main frame, and a second sub-link end rotatably connected to the sub-frame above the first sub-link end, and when the sub-frame rotates, it rotates around the first sub-link end. The above main link is, It includes a first main link end rotatably connected to the main frame, and a first main link end rotatably connected to the subframe above the first main link end, and when the subframe rotates, it rotates around the first main link end. The above elastic member is, It includes a first elastic member cutting part that is rotatably connected to the main frame, and a second elastic member cutting part that is rotatably connected to the main link from below the first elastic member cutting part, and when the subframe rotates, it rotates around the first elastic member cutting part. The first elastic member section is positioned above the first sub-link section and the first main link section. Bed.

4. In paragraph 1, The above main link is, A lower main link part rotatably connected to the above main frame; An upper main link portion rotatably connected to the above subframe; and A main link bending portion having a curved shape and connected between the lower main link portion and the upper main link portion so that the lower main link portion and the upper main link portion are arranged out of alignment with each other, and is arranged on the upper front side of the main frame when the subframe is in the second state, and is arranged on the lower side of the main frame when the subframe is in the first state. Bed.

5. In paragraph 4, The above lower main link section is, When the subframe is in the second state, the upper side is tilted forward so as to form a predetermined first angle with an imaginary line extending in the vertical direction, The above upper main link section is, When the subframe is in the second state, the upper side is tilted forward to form a second angle smaller than the first angle with respect to the virtual line. Bed.

6. In paragraph 5, The above sublink is, A lower sub-link part rotatably connected to the main frame; and Further comprising an upper sub-link portion rotatably connected to the above sub-frame, The above sub-link bending portion is connected between the lower sub-link portion and the upper sub-link portion so that the lower sub-link portion and the upper sub-link portion are arranged out of alignment with each other, The above lower sub-link part is, When the above subframe is in the second state, the upper side is tilted forward to form a third angle smaller than the second angle with respect to the virtual line, The above upper sub-link part is, When the above subframe is in the second state, it is arranged parallel to the horizontal direction, Bed.

7. In paragraph 1, The above elastic member is, When the subframe is rotated and the subframe is spaced a predetermined distance from the upper side of the main frame, the subframe is oriented in a direction corresponding to the extension direction of at least a part of the main link. Bed.

8. In paragraph 1, The subframe further includes a damper that contracts when the subframe is rotated and rises, and extends when the subframe is lowered, thereby reducing the rotation speed of the subframe. Bed.

9. In paragraph 8, The above damper, It is arranged on the inside of the elastic member and rotates together with the elastic member. Bed.

10. In paragraph 1, Further comprising a damper that is supported by the main link and the main frame, and rotates forward and backward with respect to the main frame so as to extend when the subframe is rotated and raised, and contract when the subframe is lowered, thereby reducing the rotational speed of the subframe. The center of rotation of the above damper is positioned lower than the main link and the sub link. Bed.

11. In paragraph 10, The above main link is, It includes a first main link end rotatably connected to the main frame, and a second main link end rotatably connected to the subframe above the first main link end, and when the subframe rotates, it rotates around the first main link end. The above sublink is, It includes a first sub-link end rotatably connected to the main frame, and a second sub-link end rotatably connected to the sub-frame above the first sub-link end, and when the sub-frame rotates, it rotates around the first sub-link end. The above damper, It includes a first damper end rotatably connected to the main frame, and a second damper end rotatably connected to the main link at a position above the first damper end, and when the subframe rotates, it rotates around the first damper end. The first damper end is positioned lower than the first sub-link end and the first main link end. Bed.

12. In paragraph 11, The above elastic member is, It includes a first elastic member cutting part that is rotatably connected to the main frame, and a second elastic member cutting part that is rotatably connected to the main link from below the first elastic member cutting part, and when the subframe rotates, it rotates around the first elastic member cutting part. The above second damper end When the above subframe is in the second state, it is positioned in front of the second elastic member cutting part, When the above subframe is in the first state, it is positioned rearward of the second elastic member cutting portion. Bed.

13. In paragraph 10, The above main link is, Placed between the elastic member and the damper in the left-right direction, Bed.

14. In paragraph 10, The above damper, When the subframe is rotated and the subframe is spaced a predetermined distance from the upper side of the main frame, the subframe is oriented in a direction corresponding to the extension direction of at least a part of the main link. Bed.

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