JP4892279B2 - Mattress equipment - Google Patents

Description

  The present invention relates to a mattress device used for a bed or the like.

  For example, a mattress device used for a bed has a spring unit formed by assembling a spring body such as a coil spring so that a planar shape is rectangular, and the upper and lower surfaces of the spring unit are formed of urethane foam or the like. The elastic sheet is laminated, and the laminated body is covered with an exterior body in which a fabric is sewn in a bag shape.

  A user who is supine on the top surface of the mattress device may read a book or watch television in a supine posture. In that case, reading or watching TV is easier when the head is slightly lifted than when it is level.

  In the conventional mattress device, since the user's head cannot be held in a raised state, in order for the user to raise the head, the cushion is folded and sandwiched under the pillow. . However, if the head is lifted in such a manner, the stability may be poor, or the neck may be strongly bent, which may cause fatigue.

Therefore, a mattress device disclosed in Patent Document 1 has been proposed. The mattress device disclosed in Patent Document 1 is provided with a fixed hook-shaped member and a movable hook-shaped member integrally connected to the spring unit on both sides in the width direction of the spring unit, and the movable hook-shaped member is fixed. It stands at a predetermined angle with respect to the bowl-shaped member, and is held at the standing angle by the hinge mechanism. Accordingly, one end of the spring unit can be bent and held at a predetermined rising angle, so that the user can stably place the head on the bent portion.
JP 2004-261214 A

  According to the mattress device having the configuration shown in Patent Document 1, since one end of the spring unit can be reliably supported in a state where the spring unit is bent by the hinge mechanism, the user can place the head at the bent portion of the spring unit. The posture supported by can be easily maintained.

  In patent document 1, in order to make it easy to bend one end part of a spring unit, the frame line provided in the peripheral part of the upper and lower surfaces of a spring unit is cut | disconnected by the bent part of a spring unit, and a frame is made to be bent. The wire is not bent.

  However, even if the frame line is cut so that the frame line does not become a resistance when bent, the spring unit itself becomes a bending resistance to bend one end of the spring unit. For this reason, one end of the spring unit may not be easily bent with a light force.

  Moreover, the user often wants to bend one end of the spring unit while lifting the head while lying on the mattress device. However, in such a case, since the bending operation of the spring unit is performed in a supine posture, it is difficult to apply a large force, so it is strongly desired that the bending operation of the spring unit can be performed with a light force. ing.

  An object of the present invention is to provide a mattress device in which one end of a spring unit can be easily bent with a light force.

The present invention provides a first spring unit portion provided at one end portion in the longitudinal direction and a portion separated from the first spring unit portion and the first spring unit portion and a predetermined portion excluding the one end portion in the longitudinal direction. A spring unit having a second spring unit portion provided through a gap of
A movable hook-shaped member provided integrally with the first spring unit on at least both sides in the width direction of the first spring unit;
A fixed hook-shaped member provided integrally with the second spring unit portion on at least both sides in the width direction of the second spring unit portion;
A hinge mechanism connected to the fixed rod-shaped member so that the movable rod-shaped member can be rotated and held at a predetermined rotation angle;
An elastic sheet laminated on at least the upper and lower surfaces of the spring unit;
An exterior body covering the laminate of the elastic sheet and the spring unit is provided,
The elastic sheet is provided on both the upper surface and the lower surface of the spring unit, and the elastic sheet is deformed into the gap in the gap between the first spring unit portion and the second spring unit portion. A mattress device is provided with a reinforcing elastic member for prevention .

The present invention provides a first spring unit portion provided at one end portion in the longitudinal direction and a portion separated from the first spring unit portion and the first spring unit portion and a predetermined portion excluding the one end portion in the longitudinal direction. A spring unit having a second spring unit portion provided through a gap of
A movable hook-shaped member provided integrally with the first spring unit on at least both sides in the width direction of the first spring unit;
A fixed hook-shaped member provided integrally with the second spring unit portion on at least both sides in the width direction of the second spring unit portion;
A hinge mechanism connected to the fixed rod-shaped member so that the movable rod-shaped member can be rotated and held at a predetermined rotation angle;
An elastic sheet laminated on at least the upper and lower surfaces of the spring unit;
An exterior body covering the laminate of the elastic sheet and the spring unit is provided,
The elastic sheet is provided on both the upper surface and the lower surface of the spring unit, and the portion of the elastic sheet covering the gap between the first spring unit portion and the second spring unit portion is the first spring. The elastic member covering the upper surface of the spring unit is connected by a connecting member that prevents the elastic sheet covering the upper surface of the spring unit when the unit portion is rotated in the upward direction with respect to the second spring unit portion. In the mattress device.

The present invention provides a first spring unit portion provided at one end portion in the longitudinal direction and a portion separated from the first spring unit portion and the first spring unit portion and a predetermined portion excluding the one end portion in the longitudinal direction. A spring unit having a second spring unit portion provided through a gap of
A movable hook-shaped member provided integrally with the first spring unit on at least both sides in the width direction of the first spring unit;
A fixed hook-shaped member provided integrally with the second spring unit portion on at least both sides in the width direction of the second spring unit portion;
A hinge mechanism connected to the fixed rod-shaped member so that the movable rod-shaped member can be rotated and held at a predetermined rotation angle;
An elastic sheet laminated on at least the upper and lower surfaces of the spring unit;
An exterior body covering the laminate of the elastic sheet and the spring unit is provided,
The hinge mechanism has a first arm and a second arm that are pivotably connected to be held at a predetermined pivot angle,
The mattress device is characterized in that the movable hook-like member is connected and fixed to the first arm, and the fixed hook-like member is slidably connected to the second arm .

  According to this invention, the spring unit is divided into the first spring unit portion and the second spring unit portion, and these are arranged with a predetermined gap and connected by the hinge mechanism. When the bending is raised, the spring unit does not become a bending resistance, so that the bending operation can be easily performed with a light force.

  1 to 6 show a first embodiment of the present invention. FIG. 1 is a perspective view showing a state in which a mattress device 1 is placed on a floor plate 3 of a bed 2. The mattress device 1 has a longitudinal end 1 a located on the headboard 4 side of the bed 2 in a predetermined direction. It can be raised and held at an angle of.

  The mattress device 1 has a spring unit 5 as shown in FIGS. The spring unit 5 is divided into a first spring unit portion 7 provided at one end portion in the longitudinal direction of the mattress device 1 and a second spring unit portion 8 provided at other portions. The first and second spring unit portions 7 and 8 are disposed through a gap 9 having a predetermined size.

In the first and second spring unit portions 7 and 8, a plurality of spring bodies 12 formed by continuously forming a plurality of coil portions 11 whose axes are parallel by a single wire are arranged in parallel in the width direction of the mattress device 1. ing. The upper and lower ends of adjacent spring bodies 12 are connected by a helical wire 13. Furthermore, a frame line 14 is connected by a clip 15 to the entire length of the peripheral edge portions of the upper and lower surfaces of the spring unit portions 7 and 8.
Note that the frame line 14 may be provided along three side edges excluding the opposing one side edge of the first spring unit portion 7 and the second spring unit portion 8.

  On the three sides of the first spring unit portion 7 and the second spring unit portion 8 except for the opposite sides, a U-shaped movable rod-like member 17 shown in FIGS. A fixed rod-shaped member 18 is provided integrally with each of the spring unit portions 7 and 8 by holding means described later.

  The movable hook-like member 17 and the fixed hook-like member 18 are formed of a pipe material, and the end portions located on both sides in the longitudinal direction of the spring unit 5 can be rotated by the hinge mechanism 21 and can be rotated a predetermined time. It is connected so that it can be held at a moving angle.

The movable hook-like member 17 and the fixed hook-like member 18 connected by the hinge mechanism 21 have a rectangular shape slightly smaller than the planar shape of the spring unit 5. As a result, the fixed rod-shaped member 17 and the movable rod-shaped member 18 provided on the outer peripheral portion of the spring unit 5 are, as shown in FIG. 4, the lower end in the axial direction of the coil portion 11 located in the peripheral portion of the spring unit 5. Between the spiral windings and is integrally held by the spring unit 5.

As shown in FIG. 6, the hinge mechanism 21 has a first arm 27 and a second arm 28 as attachment parts, one end of which is pivotally attached by a pivot 26. One end of the first connecting rod 27a is fitted and fixed to the other end of the first arm 27, and the end of the movable hook-like member 17 is externally fitted to the other end of the first connecting rod 27a. Has been fixed by welding.

  One end of the second connecting rod 28a is fitted and fixed to the end of the second arm 28, and the other end of the second connecting rod 28a is connected to the end of the fixed rod-shaped member 18. It is slidably fitted outside. Accordingly, the movable hook-shaped member 17 can move in the direction indicated by the arrow A in FIG. 6 with respect to the fixed hook-shaped member 18 together with the hinge mechanism 13.

A tooth 29 is formed at one end of the first arm 27, and a stopper 31 that engages with the tooth 29 is pivotally supported by a pin 32 at one end of the second arm 28. The stopper 31 is biased by a spring 33 in a direction to engage with the teeth 29.

  A cam plate 34 is rotatably attached to the pivot 26. A concave portion 35 and a convex portion 36 are formed on the outer peripheral surface of the cam plate 34 at a predetermined angle in the circumferential direction. The radial dimension of the convex portion 36 from the pivot 26 is formed larger than the radial dimension of the tooth 29 from the pivot 26. One end of the first arm 27 is provided with an engagement body 37 positioned in the recess 35 in a state where the stopper 31 is engaged with the teeth 29.

  Accordingly, the first arm 27 can be held at a predetermined rotation angle with respect to the second arm 28 by the engagement between the teeth 29 and the stopper 31. When the first arm 27 is rotated in the direction indicated by the arrow B in FIG. 6 and the cam plate 34 is interlocked with the rotation by the engaging body 37 that abuts one end of the concave portion 35, the cam plate 34 The stopper 31 rides on the convex portion 36 and is disengaged from the teeth 29. Thereby, the first arm 27 can be freely rotated in the direction opposite to the arrow.

  When the first arm 27 rotates in the direction opposite to the direction indicated by the arrow B, the engaging body 37 abuts against the other end of the recess 35 to rotate the cam plate 34, and the stopper 31 moves the cam plate 34. The first arm 27 can be rotated until it is disengaged from the convex portion 36 and engaged with the tooth 29, that is, until the first arm 27 is substantially horizontal with respect to the second arm 28.

  Therefore, the movable hook-like member 17 can be held in a state of standing up at a predetermined angle with respect to the fixed hook-like member 18 by the hinge mechanism 21 and can be horizontally laid down from the standing state. It is like that.

As shown in FIGS. 3 and 4, felts 41 are provided over the entire upper and lower surfaces of the spring unit 5. The peripheral part of each felt 41 is bent around the frame line 14, and is held on the frame line 14 by a clip (not shown).

  A holding cloth 43 constituting a holding means is laminated on the felt 41 provided on the lower surface of the spring unit 5. The holding cloth 43 is formed in a rectangular shape that is sufficiently larger than the planar shape of the spring unit 5, and the peripheral portion extends outward from the peripheral portion of the spring unit 5.

  The peripheral portion of the holding cloth 43 that extends from the peripheral portion of the spring unit 5 is divided into a movable hook-like member 17 and a fixed hook-like member 18 provided in the peripheral portion of the spring unit 5 as shown in FIG. Is wound from the inner peripheral side toward the outer peripheral side and returned to the peripheral portion of the lower surface of the spring unit 5.

  A portion of the holding cloth 43 facing the inner peripheral side of the flange members 17 and 18 is connected and fixed to the lower frame line 14 together with the end of the felt 41 by a clip (not shown), and is bent from the inner peripheral side to the outer peripheral side. The formed part is connected and fixed to the frame line 14 together with a part toward the inner peripheral side by a clip (not shown). Thereby, the movable hook-shaped member 17 and the fixed hook-shaped member 18 are integrally held by the spring unit 5 by the peripheral portion of the holding cloth 43.

By the movable rod-shaped member 17 and the fixing rod-shaped member 18 is integrally held in the spring unit 5, is rotated at a predetermined angle with respect to the fixed rod-shaped member 18 to the movable rod-shaped member 17 Then, the first spring unit portion 7 of the spring unit 5 is interlocked with the rotation. Thereby, the first spring unit portion 7 can be bent and raised at a predetermined angle with respect to the second spring unit portion 8. Moreover, since the peripheral portion of the holding cloth 43 is wound around the hook-shaped members 17 and 18, the hook-shaped members 17 and 18 and the coil portions 11 of the spring unit parts 7 and 8 directly collide with each other. Generation of metallic sound is prevented.

  Furthermore, the movable hook-shaped member 17 and the fixed hook-shaped member 18 are substantially U-shaped surrounding the three sides of the spring unit portions 7 and 8. Therefore, the spring unit portions 7 and 8 are prevented from being twisted in the width direction by the movable hook-like member 17 and the fixed hook-like member 18. In particular, when the movable hook-shaped member 17 is lifted together with the first spring unit portion 7, the raised first spring unit portion 7 is easily twisted in the width direction, but is prevented from swinging by the movable hook-shaped member 17. Is done.

  As shown in FIG. 3, a muffler formed by a cloth or a resin sheet is formed on one side edge of the upper surface of the first spring unit portion 7 and the second spring unit portion 8 facing each other through the gap 9. Member 44 is attached by clip 45. Thereby, when the first spring unit 7 is raised, it is prevented that one side edge of the first spring unit 7 directly collides with one side edge of the second spring unit portion 8 to generate a metallic sound.

  Two elastic sheets 46 are laminated on the felt 41 on the upper surface of the spring unit 5, and one elastic sheet 46 is laminated on the holding cloth 43 on the lower surface. That is, the elastic sheet 46 has the upper surface of the spring unit 5 thicker than the lower surface.

  The laminated body of the spring unit 5 and the elastic sheet 46 is covered with an exterior ground 47. As shown in FIGS. 3 and 4, the exterior ground 47 includes an upper mirror part 48 covering the upper surface of the spring unit 5, a lower mirror part 49 covering the lower surface, and a town part 50 covering the outer peripheral surface. . Each of the mirror parts 48 and 49 and the town part 50 has a three-layer structure in which an elastic sheet is sandwiched between the outer material and the lining, and the peripheral parts of the mirror parts 48 and 49 are tape edges on the upper and lower ends of the town part 50. 51 are integrally stitched together.

  As shown in FIG. 1, at the end of the outer body 47 corresponding to the first spring unit 7, an operating member 58 formed by bending a string-like member into a U-shape is attached to the outer end. It is sewn to the lower surface of the body 47, the midway part is sewn to the side surface, and the other end part is extended to the upper surface side. Accordingly, when the operating member 58 is pulled upward, the hinge mechanism 21 is operated, and the one end portion 1a of the mattress device 1 which is a portion of the first spring unit portion 7 can be raised.

  According to the mattress device 1 having the above configuration, the movable hook-shaped member 17 and the fixed hook-shaped member 18 are integrated with the first spring unit section 7 and the second spring unit section 8 on the outer periphery of the spring unit 5, respectively. These hook-shaped members 17 and 18 are connected by a hinge mechanism 21 so as to be rotatable and to be held at a predetermined rotation angle.

  Therefore, if the longitudinal end portion 1a of the mattress device 1 is raised, the hinge mechanism 21 is actuated, and the first spring unit portion 7 of the one end portion 1a is raised together with the movable hook-like member 17, and FIG. As shown, it is held at a predetermined elevation angle. That is, the one end 1a of the mattress device 1 can be bent upward.

  As a result, the user who is supine on the top surface of the mattress device 1 can easily maintain the posture in which the head is lifted by the one end 1a. it can.

  When the one end 1a of the mattress device 1 is raised, an operating member 58 is provided at the one end 1a. Therefore, the user can easily pull up the one end 1 a in the upward direction by the operating member 58. That is, the operation member 58 can easily raise the one end portion 1a of the mattress device 1.

  The first spring unit portion 7 provided at the one end 1 a of the mattress device 1 is separated from the second spring unit portion 8 of the other portion of the mattress device 1 through a gap 9. Therefore, a large resistance is hardly added when the one end 1a of the mattress device 1 is raised.

  That is, by dividing the spring unit 5 into the two spring unit portions 7 and 8, the first spring unit portion 7 can be raised without bending the spring unit 5. Therefore, it is possible to easily perform the operation for raising the first spring unit portion 7 with a light force.

  Thereby, for example, even when the user is in a supine posture on the mattress device 1, the user lifts the head 58 by pulling the operating member 58 with one hand or by directly lifting the one end 1a of the mattress device 1 with one hand. It is easy to use and convenient. That is, the user can rotate the one end 1a without getting off the mattress device 1.

  Thus, by dividing the spring unit 1 into the first spring unit portion 7 and the second spring unit portion 8, the one end portion 1a of the mattress device 1 can be raised almost without resistance.

  Moreover, two elastic sheets 46 are laminated and reinforced on the upper surface of the divided part of the first spring unit portion 7 and the second spring unit portion 8. Therefore, for example, a part of the user's body is less likely to fall into the gap 9 between the first spring unit portion 7 and the second spring unit portion 8, so that the first spring unit portion 7 and the second spring unit portion 2 Even if divided into the spring unit portion 8, it is possible to prevent the performance of the mattress device 1 from being deteriorated.

  When the one end 1a of the mattress device 1 is raised, the two elastic sheets 46 provided on the upper surface of the divided part of the first spring unit 7 and the second spring unit 8 are bent. Therefore, it may be difficult to bend the one end portion 1a of the mattress device 1 due to the resistance generated by the elastic sheet 46 being bent.

  However, when the elastic sheet 46 is bent and the resistance due to the reaction force is generated when the one end portion 1a of the mattress device 1 is raised, the hinge mechanism 21 is moved to the fixed hook-shaped member 18 by the resistance in FIG. Slide in the direction indicated by A. That is, the first spring unit portion 7 slides with respect to the second spring unit portion 8.

  As a result, the resistance caused by bending the elastic sheet 46 is alleviated, so that the first spring unit 7 can be easily bent and raised with a relatively light force.

  FIG. 7 shows a second embodiment of the present invention. In this embodiment, two elastic sheets 46 are laminated on each of the upper surface and the lower surface of the spring unit 5, and the gap 9 between the first spring unit portion 7 and the second spring unit portion 8 is The belt-like reinforcing elastic member 53 is provided over the entire length of the spring unit 5 in the width direction.

  The upper and lower end surfaces of the reinforcing elastic member 53 are bonded and fixed to the felt 41 provided on the upper and lower surfaces of the spring unit 5 so that the reinforcing elastic member 53 does not move or fall down in the gap 9. Yes.

According to such a configuration, the upper and lower surfaces of the mattress device 1 corresponding to the gap 9 are not only reinforced by the two elastic sheets 46 respectively provided on the upper and lower surfaces of the spring unit 5, but also the gap 9 The reinforcing elastic member 53 provided between the upper and lower elastic sheets 46 is also reinforced.
Therefore, it is possible to reliably prevent a part of the user's body from deforming the elastic sheet 46 and falling into the gap 9.

  FIG. 8 shows a third embodiment of the present invention. In this embodiment, the felt 41 provided on the upper and lower surfaces of the spring unit 5 is connected to the first spring unit portion 7 and the second spring unit portion 8. And are wound around two opposing side portions of each of the spring unit portions 7 and 8 and held by clips 42. As a result, the felt 41 has a silencing effect that prevents metal sound from being generated due to direct contact between one side of the first spring unit portion 7 and the second spring unit portion 8.

  Further, two elastic sheets 46 provided on the upper surface of the spring unit 5 and one elastic sheet 46 provided on the lower surface are formed in a string shape at the gap 9 between the first and second spring unit portions 7 and 8. The connection members 55 are connected. A display member 56 such as a button is connected to one end of a connecting member 55 protruding from the upper surface of the mattress device 1.

  Thereby, when the one end portion 1a of the mattress device 1 is bent in the upward direction, the connecting member 55 can prevent the elastic sheet 46 laminated on the upper surface of the spring unit 5 from floating.

  In addition, since the display member 56 connected to the connection member 55 is provided on the upper surface of the gap 9, the display member 56 can discriminate the bent position at the one end 1 a of the mattress device 1 at a glance. .

  In the third embodiment, the movable hook-like member connected by the hinge mechanism 21 is not provided on the lower surface of the spring unit 5 without the holding cloth 43 for holding the movable hook-like member 17 and the fixed hook-like member 18. The rectangular size formed by 17 and the fixing rod-shaped member 18 is formed slightly smaller than the planar shape of the spring unit 5. Thereby, the movable hook-shaped member 17 and the fixed hook-shaped member 18 are integrally coupled to the spring unit 5.

  In each of the above embodiments, only one end of the spring unit can be raised, but the other end may be raised in the same manner as the one end. With such a structure, a user who is supine on the mattress device can hold not only the head but also the foot part in a raised state. It is valid.

The perspective view of the mattress apparatus mounted on the bed which shows 1st Embodiment of this invention. The top view which shows the one end part of a spring unit. Sectional drawing of the part in which the clearance gap between the 1st spring unit part of the mattress device and the 2nd spring unit part was formed. Sectional drawing which shows the connection part of a spring unit, a movable hook-shaped member, and a fixed hook-shaped member. The side view which shows schematic structure of a spring unit. The sectional side view of a hinge mechanism. Sectional drawing of the part in which the clearance gap between the 1st spring unit part and the 2nd spring unit part which shows 2nd Embodiment of this invention was formed. Sectional drawing of the part in which the clearance gap between the 1st spring unit part and the 2nd spring unit part which shows the 3rd Embodiment of this invention was formed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 5 ... Spring unit, 7 ... 1st spring unit part, 8 ... 2nd spring unit part, 9 ... Gap, 17 ... Movable hook-shaped member, 18 ... Fixed hook-shaped member, 21 ... Hinge mechanism, 41 ... Felt, 44 ... Silencer member, 46 ... Elastic sheet, 47 ... Exterior body, 53 ... Reinforcing elastic member, 55 ... Connecting member, 56 ... Display member, 58 ... Actuating member.

Claims (3)

A first spring unit portion provided at one end portion in the longitudinal direction and a portion separated from the first spring unit portion and excluding the one end portion in the longitudinal direction via the first spring unit portion and a predetermined gap. A spring unit having a second spring unit provided by
A movable hook-shaped member provided integrally with the first spring unit on at least both sides in the width direction of the first spring unit;
A fixed hook-shaped member provided integrally with the second spring unit portion on at least both sides in the width direction of the second spring unit portion;
A hinge mechanism connected to the fixed rod-shaped member so that the movable rod-shaped member can be rotated and held at a predetermined rotation angle;
An elastic sheet laminated on at least the upper and lower surfaces of the spring unit;
An exterior body covering the laminate of the elastic sheet and the spring unit is provided,
The elastic sheet is provided on both the upper surface and the lower surface of the spring unit, and the elastic sheet is deformed into the gap in the gap between the first spring unit portion and the second spring unit portion. A mattress device, characterized in that a reinforced elastic member is provided . A first spring unit portion provided at one end portion in the longitudinal direction and a portion separated from the first spring unit portion and excluding the one end portion in the longitudinal direction via the first spring unit portion and a predetermined gap. A spring unit having a second spring unit provided by
A movable hook-shaped member provided integrally with the first spring unit on at least both sides in the width direction of the first spring unit;
A fixed hook-shaped member provided integrally with the second spring unit portion on at least both sides in the width direction of the second spring unit portion;
A hinge mechanism connected to the fixed rod-shaped member so that the movable rod-shaped member can be rotated and held at a predetermined rotation angle;
An elastic sheet laminated on at least the upper and lower surfaces of the spring unit;
An exterior body covering the laminate of the elastic sheet and the spring unit is provided,
The elastic sheet is provided on both the upper surface and the lower surface of the spring unit, and the portion of the elastic sheet covering the gap between the first spring unit portion and the second spring unit portion is the first spring. The elastic member covering the upper surface of the spring unit is connected by a connecting member that prevents the elastic sheet covering the upper surface of the spring unit when the unit portion is rotated in the upward direction with respect to the second spring unit portion. Mattress device. A first spring unit portion provided at one end portion in the longitudinal direction and a portion separated from the first spring unit portion and excluding the one end portion in the longitudinal direction via the first spring unit portion and a predetermined gap. A spring unit having a second spring unit provided by
A movable hook-shaped member provided integrally with the first spring unit on at least both sides in the width direction of the first spring unit;
A fixed hook-shaped member provided integrally with the second spring unit portion on at least both sides in the width direction of the second spring unit portion;
A hinge mechanism connected to the fixed rod-shaped member so that the movable rod-shaped member can be rotated and held at a predetermined rotation angle;
An elastic sheet laminated on at least the upper and lower surfaces of the spring unit;
An exterior body covering the laminate of the elastic sheet and the spring unit is provided,
The hinge mechanism has a first arm and a second arm that are pivotably connected to be held at a predetermined pivot angle,
The mattress device, wherein the movable hook-like member is connected and fixed to the first arm, and the fixed hook-like member is slidably connected to the second arm .

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