Bed transfer assistance device

Abstract

The present invention provides a bed movement assistance device that reduces the load applied to the bed due to fluctuations in the movement surface. [Solution] The bed moving assist device (1) is a bed moving assist device that assists in moving a bed. The bed moving assist device (1) comprises a drive wheel (4), a support frame (3) that supports the drive wheel (4), a connecting mechanism (7) that connects to the bed, and a linear guide mechanism (6) that connects the support frame (3) and the connecting mechanism (7) so that they can move relative to each other in the vertical direction.

Description

Technical Field

[0001] The present invention relates to a bed movement assisting device for assisting the movement of a movable bed.

Background Art

[0002] In hospitals, nursing facilities, etc., many movable beds with casters are arranged. The work of moving such a bed is usually carried out by two people, but due to a shortage of manpower, it is often carried out by one person, and the burden on the person in charge of moving is large. In order to reduce such a burden, a movement assisting device that generates a driving force to assist the movement of the bed has been developed.

[0003] For example, Patent Document 1 describes a type of movement assisting device attached to the front end of a bed during movement.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, such a movement assisting device causes the bed during movement to be affected by variations in the movement surface such as steps, slopes, grooves, etc., and applies a load to the bed.

[0006] For example, when the driving wheel of the movement assisting device reaches an upward inclined surface while the caster on the rear side of the bed is on a flat floor surface, the caster on the front side of the bed will be in a floating state even if it has reached the inclined surface. Therefore, the load of the bed cannot be supported by the front caster, and a load is applied to a part of the bed such as the frame to which the movement assisting device is connected. Since such a part of the bed is not designed to withstand a high load, there is a risk of damage.

[0007] Furthermore, when the drive wheels of the mobility assist device and the front casters of the bed reach a downward slope, the front casters and the rear casters of the bed, which are on a flat floor, primarily support the weight of the bed, while the mobility assist device is slightly elevated. As a result, the front casters end up supporting the weight of the mobility assist device along with the weight of the bed, and are pressed firmly against the slope, increasing the load.

[0008] One aspect of the present invention aims to provide a bed movement assistance device that reduces the load applied to the bed due to fluctuations in the moving surface. [Means for solving the problem]

[0009] To solve the above problems, a bed movement assist device according to one aspect of the present invention is a bed movement assist device for assisting the movement of a bed, comprising: a drive wheel; a support part for supporting the drive wheel; a connecting part that is detachably connected to the bed; and a connecting mechanism that connects the support part and the connecting part so that they can move relative to each other in the vertical direction.

[0010] According to the above configuration, as the height of the support unit is displaced vertically along with the drive wheels due to fluctuations in the floor height, the connecting unit moves in the opposite direction to the direction of the support unit's displacement. For example, if the height of the support unit is displaced upward, the connecting unit moves downward. This allows the wheels of the bed adjacent to the drive wheels to also make contact with the floor surface in accordance with the height fluctuations of the support unit. Conversely, if the height of the support unit is displaced downward, the connecting unit moves upward. This also allows the wheels of the bed adjacent to the drive wheels to make contact with the floor surface in accordance with the height fluctuations of the support unit.

[0011] Therefore, regardless of the condition of the floor surface, it is possible to avoid significant changes in the load (stress) applied to the parts connected to the bed's joints, such as the frame.

[0012] In the bed movement assist device, the connecting mechanism may include a linear guide mechanism having a fixed part that is fixed to the support part and a movable part that is movable relative to the fixed part.

[0013] According to the above configuration, a coupling mechanism can be constructed using a general linear guide mechanism.

[0014] In the bed movement assist device, the movable part is provided such that the connecting part can be moved to a position higher than the height of the upper end of the part to be connected on the bed, and the distance between the support part and the connecting part may be changed in response to the displacement of the support part.

[0015] In the above configuration, the movable part of the connecting mechanism can be easily connected to the connected part by moving the movable part to a position higher than the height of the connected part. Furthermore, by changing the distance between the support part and the connecting part in response to the displacement of the support part, the connecting part can be moved in the opposite direction to the vertical displacement of the support part so as not to put a load on the connected part of the bed.

[0016] In the bed movement assist device, the connecting portion may include an upper holding portion provided on the linear guide mechanism and holding the upper end of the connected portion on the bed, and a lower holding portion provided so as to be vertically adjustable and holding the lower end of the connected portion.

[0017] According to the above configuration, the connecting part is connected according to the height of the upper end of the part to be connected on the bed. This allows the bed movement assist device to be connected according to the height of the upper end of each part, even for beds where the height of the part to be connected can be changed to any height, or for beds where the heights of the parts to be connected differ. Therefore, a highly versatile bed movement assist device can be provided.

[0018] The bed moving assist device may include a handle for moving the connecting portion up and down, a state switching mechanism for switching between a first state in which both the upper holding portion and the lower holding portion are moved up and down by the handle, and a second state in which only the lower holding portion is moved up and down by the handle, and a lever provided on the handle for operating the state switching mechanism to switch between the first state and the second state.

[0019] In the above configuration, the user can switch between the first and second states by operating a state switching mechanism using a lever on the handle while still holding the handle. This eliminates the need for the user to release their hand from the handle and switch to another control unit when moving the upper and lower holding parts up and down simultaneously, or when moving only the lower holding part up and down. This simplifies the work procedure and reduces the amount of work required. Therefore, even if the height of the connected part differs for each bed, the height of the upper and lower holding parts can be easily adjusted.

[0020] In the bed movement assist device, the state switching mechanism may include a shaft that moves vertically in conjunction with the movable part and is arranged in the direction of movement of the movable part, and a fixing mechanism that is provided in conjunction with the lower holding part, is fixed to the shaft when switched to the first state, and is not fixed to the shaft when switched to the second state.

[0021] According to the above configuration, when the lower holding part is switched to the first state, it moves up and down together with the upper holding part and the shaft due to the movement of the movable part, while when the system is switched to the second state, the lower holding part can move up and down along the shaft. This allows the lower holding part to move independently of the upper holding part.

[0022] In the aforementioned bed movement assist device, the drive wheel may be a single wheel.

[0023] The above configuration allows for a reduction in the number of parts. Furthermore, it is only necessary to absorb the displacement of the connection point by the vertical coupling mechanism relative to the floor surface, and there is no torsional displacement, such as when one of the two drive wheels is on an inclined surface. Therefore, the drive wheels can stably provide propulsion to the bed. [Effects of the Invention]

[0024] According to one aspect of the present invention, it is possible to provide a bed movement assisting device that reduces the load applied to the bed due to fluctuations in the moving surface.

Brief Description of the Drawings

[0025] [Figure 1] It is a side view showing the configuration of a bed whose movement is assisted by the bed movement assisting device according to Embodiment 1 of the present invention. [Figure 2] It is a perspective view showing the configuration of the bed movement assisting device. [Figure 3] It is a perspective view showing the internal configuration of the bed movement assisting device. [Figure 4] It is a perspective view showing another internal configuration of the bed movement assisting device. [Figure 5] It is a side view showing the state in which the bed movement assisting device is attached to the bed. [Figure 6] It is a longitudinal sectional view showing the state of the bed movement assisting device when the bed to which the bed movement assisting device is attached moves from a flat floor surface to an upwardly inclined floor surface. [Figure 7] It is a longitudinal sectional view showing the state of the bed movement assisting device when the bed to which the bed movement assisting device is attached moves from a flat floor surface to a downwardly inclined floor surface. [Figure 8] It is a perspective view showing the configuration of the bed movement assisting device according to Embodiment 2 of the present invention. [Figure 9] It is a perspective view showing another configuration of the bed movement assisting device in FIG. 8. [Figure 10] It is a perspective view showing the internal configuration of the bed movement assisting device in FIG. 8. [Figure 11] It is a top view showing the configuration of the bed movement assisting device in FIG. 8. [Figure 12] It is a side view showing the configuration of the operating mechanism and the state switching mechanism in the bed movement assisting device in FIG. 8. [Figure 13] It is a partial sectional view showing the configuration of the slide lock mechanism in the state switching mechanism. [Figure 14]This is a plan view showing the configuration of the plate member in the slide lock mechanism described above. [Figure 15] This diagram shows the procedure for connecting the bed moving assist device shown in Figure 8 to the bed. [Modes for carrying out the invention]

[0026] [Embodiment 1] One embodiment of the present invention will be described in detail below.

[0027] <Bed configuration> First, let's describe the configuration of the bed 100. Figure 1 is a side view showing the configuration of the bed 100, whose movement is assisted by the bed movement assist device according to this embodiment.

[0028] As shown in Figure 1, the bed 100 is a movable bed used for medical or nursing care purposes, and comprises a movable frame 101, a head frame 102, a foot frame 103 (connected part), a base frame 104, casters 105 and 106, and a lifting mechanism 107.

[0029] The movable frame 101 is a frame for supporting a person lying down. The movable frame 101 can move vertically relative to the base frame 104 by means of a lifting mechanism 107.

[0030] The head frame 102 is a fence-like member provided at the end of the movable frame 101 on the side where the head of a person lying down is located. The foot frame 103 is a fence-like member provided at the end of the movable frame 101 on the side where the feet of a person lying down are located. The head frame 102 and the foot frame 103 are detachably connected to the movable frame 101 by a locking mechanism.

[0031] The head frame 102 and foot frame 103 may be replaced with plate-shaped members.

[0032] The base frame 104 is a frame that supports the movable frame 101 and is located below the movable frame 101.

[0033] The casters 105 are provided one at each end of the bed 100 in the width direction at the foot frame 103 side end of the base frame 104. Each caster 105 has a rotating part 105a and a wheel 105b. The rotating part 105a is provided so as to be able to rotate 360° in the horizontal plane relative to the base frame 104. The wheel 105b is supported at the lower end of the rotating part 105a so as to be able to rotate about an axis perpendicular to the central axis of rotation of the rotating part 105a.

[0034] The casters 106 are provided one at each end of the bed 100 in the width direction at the head frame 102 side end of the base frame 104. Each caster 106 has a rotating part 106a and a wheel 106b. The rotating part 106a is provided so as to be able to rotate 360° in the horizontal plane relative to the base frame 104. The wheel 106b is supported at the lower end of the rotating part 106a so as to be able to rotate about an axis perpendicular to the axis that is the center of rotation of the rotating part 106a.

[0035] The lifting mechanism 107 is a mechanism that supports the movable frame 101 so that it can be raised and lowered relative to the base frame 104. The lifting mechanism 107 includes a pair of connecting members 107a, a pair of connecting members 107b, support shafts 107c to 107f, and a central shaft 107g.

[0036] Support shaft 107c is an axle that spans between the two sides of the movable frame 101 near the foot frames 103 on both sides. Support shaft 107d is an axle that spans between the two sides of the movable frame 101 near the head frames 102 on both sides. Support shaft 107e is an axle that spans between the two sides of the base frame 104 near the casters 105 on both sides. Support shaft 107f is an axle that spans between the two sides of the base frame 104 near the casters 106 on both sides.

[0037] The pair of connecting members 107a and 107b are positioned such that one is located on one side of the bed 100 and the other on the other side of the bed 100. Furthermore, the connecting members 107a and 107b are positioned so as to intersect each other in the center.

[0038] A pair of connecting members 107a are rotatably supported on a support shaft 107c at one end and rotatably supported on a support shaft 107f at the other end. A pair of connecting members 107b are rotatably supported on a support shaft 107d at one end and rotatably supported on a support shaft 107e at the other end.

[0039] The central axis 107g is positioned to extend in the width direction of the bed 100. The central axis 107g is positioned to pass through the respective intersecting central parts of the connecting members 107a and 107b.

[0040] Here, the support shafts 107c and 107d provided on the movable frame 101 are arranged to move through elongated holes (not shown) formed in the longitudinal direction of the movable frame 101 on the side of the movable frame 101, so that the connecting members 107a and 107b can rotate. Alternatively, the support shafts 107e and 107f provided on the base frame 104 are arranged to move through elongated holes (not shown) formed in the longitudinal direction of the base frame 104 on the side of the base frame 104, so that the connecting members 107a and 107b can rotate.

[0041] The bed 100, configured as described above, allows the movable frame 101 to be raised and lowered within a specified range relative to the base frame 104 by the lifting mechanism 107. In addition, the bed 100 can move forward, backward, sideways, and around curves by the freely changing direction of the casters 105 and 106.

[0042] <Configuration of the bed transfer assistance device> Figure 2 is a perspective view showing the configuration of the bed relocation assistance device 1. Figure 3 is a perspective view showing the internal configuration of the bed relocation assistance device 1. Figure 4 is a perspective view showing other internal configurations of the bed relocation assistance device 1. Figure 5 is a side view showing the bed relocation assistance device 1 attached to the bed 100. The bed relocation assistance device 1 is a device that assists in the movement of the bed 100 and is attached to the foot frame 103, which is on the front side when the bed 100 is moved.

[0043] As shown in Figures 1 to 4, the bed movement assist device 1 has as its main components a housing 2, a support frame 3 (support part), a drive wheel 4, a drive mechanism 5, a linear guide mechanism 6 (coupling mechanism), and a connecting mechanism 7 (connecting part). The bed movement assist device 1 also has a handle 8, a pair of spacers 9, a pair of rollers 10, and a grip 11. Furthermore, as a control function, the bed movement assist device 1 has a controller 13, as shown in Figure 5.

[0044] The housing 2 is an exterior body that covers almost the entire bed movement assist device 1. The housing 2 has a front portion 21 and an opposing portion 22. The housing 2 is formed so that the front portion 21 and the opposing portion 22 can be separated and joined at a dividing line 23.

[0045] The front section 21 is the front part of the bed movement assist device 1 when it is attached to the bed 100.

[0046] The opposing portion 22 is the part that faces the front side of the bed 100, including the foot frame 103. The lower part of the opposing portion 22 is formed to protrude from the upper part in order to house the drive wheels 4.

[0047] The support frame 3 is a frame that supports the various components that make up the bed movement assist device 1. The support frame 3 has a main body 3a, a pair of upper protrusions 3b, a support plate 3c, and a drive system housing 3d.

[0048] The main body 3a is a portion formed mainly inside the front portion 21 of the housing 2, and also includes a portion that protrudes towards the opposing portion 22 of the housing 2. The drive wheels 4 and the drive mechanism 5 are arranged in the lower part of the main body 3a. The support plate 3c is arranged in the upper part of the main body 3a. Components such as a power supply unit are arranged on the support plate 3c, although these are not shown in the diagram. The drive system housing 3d is fixed to the lower surface of the support plate 3c. The drive system housing 3d is a box-shaped member with an open lower end, and its upper end surface is fixed to the lower surface of the support plate 3c. The drive system housing 3d supports the drive wheels 4.

[0049] The pair of upper projections 3b are spaced apart from each other and extend upward from the area on the main body 3a where the support plate 3c is located. The upper projections 3b are connected to a plurality of horizontal members that form the upper end of the main body 3a at approximately the center. The upper projections 3b support the linear guide mechanism 6 and the connecting mechanism 7, which will be described later.

[0050] The drive wheel 4 is a wheel that rolls on a moving surface such as a floor or road surface, and consists of only one wheel. However, the drive wheel 4 is not limited to one wheel; it may consist of two wheels.

[0051] The drive mechanism 5 includes a motor that drives the drive wheels 4, a transmission mechanism that transmits the driving force generated by the motor to the drive wheels 4, and the like. The drive mechanism 5 is located inside the drive system housing 3d and is fixed to the drive system housing 3d. The drive mode of the drive wheels 4 by the drive mechanism 5 is not particularly limited. For example, possible drive modes include a mode in which the driving force is transmitted to the shaft of the drive wheel 4 by a gear group, and a mode in which the driving force is transmitted to a pair of gears provided on both sides of the drive wheel 4 via pulleys.

[0052] The linear guide mechanism 6 is a mechanism that moves linearly in the vertical direction relative to the support frame 3. The linear guide mechanism 6 has a pair of nuts 61 (fixed part) and a sliding body 62 (movable part). The sliding body 62 is provided to be movable relative to the pair of nuts 61.

[0053] The linear guide mechanism 6 is configured as follows to connect the support frame 3 and the connecting mechanism 7 so that they can move relative to each other in the vertical direction. Specifically, the linear guide mechanism 6 connects the support frame 3 and the connecting mechanism 7 in the direction of travel of the linear guide mechanism 6, and moves the connecting mechanism 7 in the opposite direction to the vertical displacement of the height of the support frame 3.

[0054] The pair of nuts 61 are positioned vertically between the pair of upper protrusions 3b on the support frame 3 and are supported by the pair of upper protrusions 3b. The nuts 61 have grooves formed along both side edges, extending over their entire vertical length. The grooves have a partially circular cross-section in the horizontal direction, with a portion of the circle missing.

[0055] The slide body 62 is a strip-shaped member having a predetermined length and thickness. The slide body 62 has protrusions (not shown) formed along its entire length on both side edges. The protrusions have a circular cross-section in the horizontal direction so that they gently fit into the groove of the nut 61. The slide body 62 becomes movable in the direction that the groove of the nut 61 extends as the protrusions gently fit into the groove of the nut 61. The nut 61 receives force from the slide body 62 on the inner surface of the groove.

[0056] As shown by the arrows in Figure 5, the sliding body 62 is provided so that the connecting mechanism 7 can be moved to a position higher than the height of the upper end of the foot frame 103 on the bed 100. The sliding body 62 also changes the distance between the support frame 3 and the connecting mechanism 7 in response to the height displacement of the support frame 3.

[0057] The linear guide mechanism 6 is configured such that a nut 61 is fixed to a pair of upper protrusions 3b and a sliding body 62 moves relative to the nut 61, but it is not limited to this configuration. Specifically, the linear guide mechanism 6 may be configured such that the sliding body 62 is fixed to a pair of upper protrusions 3b as a guide rail, and the nut 61 functions as a slider that moves relative to the guide rail.

[0058] Furthermore, the linear guide mechanism 6 is not limited to the above configuration in which the load of the slide body 62 is received by the groove surface of the nut 61; a mechanism in which the load of the movable part is received by a ball, roller, or the like may also be used.

[0059] The connection mechanism 7 is a mechanism for detachably connecting the bed movement assist device 1 to the bed 100. The connection mechanism 7 includes an upper holding mechanism 71 and a lower holding mechanism 72.

[0060] The upper holding mechanism 71 is a mechanism that holds the upper end of the foot frame 103 of the bed 100. The upper holding mechanism 71 has a fixing plate 71a and a pair of upper hooks 71b (upper holding parts).

[0061] The fixing plate 71a is a rectangular plate-shaped member. The fixing plate 71a is fixed to the upper end of the side of the slide body 62 of the linear guide mechanism 6 that faces the bed 100. A pair of upper hooks 71b are fixed to both end faces of the fixing plate 71a. The pair of upper hooks 71b are formed in a hook shape that extends from the upper end of the vertically extending fixing portion fixed to the fixing plate 71a, on the side opposite to the main body 3a of the housing 2, and then bends downward. Due to this structure, the pair of upper hooks 71b engage with the upper end of the foot frame 103.

[0062] The lower holding mechanism 72 is a mechanism that holds the lower end of the foot frame 103 of the bed 100. The lower holding mechanism 72 is also provided so that its vertical position can be adjusted. The lower holding mechanism 72 has a fixed rail 721, a lifting section 722, and a lifting drive section 723.

[0063] The fixed rail 721 is a strip-shaped member having a fixed width and a fixed length shorter than the sliding body 62 of the straight guide mechanism 6. Like the sliding body 62, the fixed rail 721 has a pair of protrusions formed along its entire length on both end edges. The protrusions have a circular cross-section in the horizontal direction.

[0064] The lifting section 722 is provided to be able to move up and down relative to the fixed rail 721. The lifting section 722 has a lifting body 722a and a pair of lower hooks 722b (lower holding parts). The lifting body 722a, like the nut 61 of the linear guide mechanism 6, has grooves formed on both side edges that extend over the entire length in the vertical direction. The grooves have a partially circular cross-section in the horizontal direction, with a part of the circle missing. The lifting body 722a can move up and down on the fixed rail 721 in the direction in which the protrusions of the fixed rail 721 extend, by allowing the protrusions of the fixed rail 721 to slide into the grooves.

[0065] A pair of lower hooks 722b are fixed to both sides of the surface of the lifting body 722a facing the bed 100. The pair of lower hooks 722b are formed in a hook shape that extends from approximately the center of the vertically extending fixing portion fixed to the lifting body 722a toward the opposite side of the main body portion 3a of the housing 2, and then bends upward. Due to this structure, the lower hooks 722b engage with the lower end of the foot frame 103.

[0066] The lifting drive unit 723 drives the lifting unit 722 up and down using a winch. The lifting drive unit 723 includes a pair of eye bolts 723a, a pair of wires 723b, a winding mechanism 723c, and an operating knob 723d.

[0067] A pair of eyebolts 723a are fixed to both ends of the sliding body 62 on the lifting body 722a. A pair of wires 723b have their lower ends hooked onto the pair of eyebolts 723a and their upper ends wound onto the hoisting mechanism 723c.

[0068] The hoisting mechanism 723c raises the lifting body 722a by winding up a pair of wires 723b, and lowers the lifting body 722a by winding down the pair of wires 723b. The hoisting mechanism 723c is fixed to the upper end of the sliding body 62.

[0069] The winding mechanism 723c winds up the pair of wires 723b when the user turns the operating knob 723d, for example, to the right, and locks the position of the wires 723b when the user releases the operating knob 723d. The winding mechanism 723c also winds down the pair of wires 723b when the user turns the operating knob 723d, for example, to the right.

[0070] The lifting drive unit 723 may use another mechanism, such as an air cylinder, instead of a winch to raise and lower the lifting body 722a.

[0071] The handle 8 is provided for the user to hold when lifting or lowering the pair of upper hooks 71b according to the height of the foot frame 103 when attaching the bed moving assist device 1 to the foot frame 103 of the bed 100. The handle 8 is fixed to the bed 100 side of the winding mechanism 723c described above.

[0072] A pair of spacers 9 are provided to maintain a constant distance between the foot frame 103 and the housing 2 of the bed movement assist device 1 when the bed movement assist device 1 is mounted on the bed 100. The spacers 9 are attached to the upper projection 3b of the support frame 3 so as to be exposed from the opposing portion 22 of the housing 2.

[0073] The pair of rollers 10 are components used to roll the bed moving assist device 1 when transporting it. The pair of rollers 10 are rotatably attached to the lower corners of the main body portion 3a of the support frame 3.

[0074] The handle 11 is provided for the user to hold when carrying the bed transfer assist device 1.

[0075] The controller 13 is a device that operates and controls the bed movement assist device 1. The controller 13 has an operating unit (not shown) and a control unit.

[0076] The control unit has levers and the like for user operation. The control unit is provided for selecting the direction of forward, backward, lateral movement, and left / right curves of the bed movement assist device 1. The control unit is fixed to the upper end of the head frame 102.

[0077] The control unit controls the operation of the drive mechanism 5 based on the operation signals output from the control unit in response to user operations. The control unit may be fixed to the upper end of the head frame 102, like the control unit, but it may also be located at other locations on the bed 100. Communication between the control unit and the drive mechanism 5 may be conducted via wire or wirelessly.

[0078] The controller 13 does not necessarily have an operating section. For example, the controller 13 has a pair of sensors, such as pressure sensors, that the user grasps with both hands. These sensors are located at the upper end of the head frame 102. The controller 13 controls the drive mechanism 5 according to the detection signals output from the sensors, depending on how much force the user applies to the sensors.

[0079] For example, in the case of forward movement, the controller 13 detects the force with which the user pushes the head frame 102 with both hands, determines that it is moving forward, and controls the drive mechanism 5 to move forward. Also, in the case of backward movement, the controller 13 detects the force with which the user pulls the head frame 102 with both hands, determines that it is moving backward, and controls the drive mechanism 5 to move backward.

[0080] <Operation of the bed transfer assist device> Figure 6 is a longitudinal cross-sectional view showing the state of the bed movement assist device 1 when the bed 100 to which the bed movement assist device 1 is attached moves from a flat floor surface F to an upward-sloping floor surface F. Figure 7 is a longitudinal cross-sectional view showing the state of the bed movement assist device 1 when the bed 100 to which the bed movement assist device 1 is attached moves from a flat floor surface F to a downward-sloping floor surface F.

[0081] First, we will explain the operation of the bed 100 when the bed repositioning assist device 1 is attached to the bed 100.

[0082] The user holds the handle 8 and pulls up or pushes down the sliding body 62 of the linear guide mechanism 6 so that the upper hook 71b is positioned higher than the height of the upper end of the foot frame 103. In response to such an operation, the sliding body 62 moves upward or downward relative to the nut 61.

[0083] The user moves the upper hook 71b to a position higher than the upper end of the foot frame 103, thereby moving the bed movement assist device 1 to a position where it contacts the foot frame 103. In this state, the user holds the handle 8 and pushes down the sliding body 62. This causes the sliding body 62 to move downward, and the upper hook 71b engages with the upper end of the foot frame 103.

[0084] Next, the user operates the operating knob 723d of the hoisting mechanism 723c so that the lower hook 722b moves upward. This operation causes the hoisting mechanism 723c to wind up the wire 723b. As a result, the hoisting mechanism 723c raises the lifting section 722. Consequently, the lower hook 722b engages with the lower end of the foot frame 103. In this state, the winding of the wire 723b is locked. In this way, the bed moving assist device 1 is attached to the bed 100.

[0085] As shown in Figure 5, the bed movement assist device 1, which is attached to the bed 100, generates forward propulsion through its drive wheels 4 when the bed 100 is moving forward on a flat floor surface F. This reduces the force with which the user pushes the bed 100. In this state, the wheels 105b and 106b of the bed 100 support the load of the bed 100, while the drive wheels 4 of the bed movement assist device 1 support the load of the bed movement assist device 1.

[0086] Furthermore, when the bed 100 equipped with the bed movement assist device 1 is moved forward, the floor surface F may change from a flat surface to an upward-sloping surface, as shown in Figure 6. In the state shown in Figure 6, the wheel 106b located at the rear in the direction of movement is on the flat surface of the floor surface F, and the wheel 105b located at the front in the direction of movement is on the upward-sloping surface of the floor surface F.

[0087] In this state, as the height of the drive wheels 4 in the bed movement assist device 1, which moves in front of the bed 100, is displaced upward, the height of the support frame 3 is also displaced upward. In contrast, the sliding body 62 of the linear guide mechanism 6 is connected to the bed 100 by the connecting mechanism 7, and therefore moves diagonally downward perpendicular to the upward inclined surface, as shown by the arrow in Figure 6.

[0088] In this way, the sliding body 62 moves downward, in the opposite direction to the upward displacement of the support frame 3. As a result, the distance between the connecting mechanism 7 and the support frame 3 becomes shorter than the distance when the bed moving assist device 1 is moving on a flat floor surface F. Therefore, the loads applied to the wheels 105b of the bed 100 and the drive wheels 4 of the bed moving assist device 1 remain almost unchanged compared to when the bed 100 and the bed moving assist device 1 are moving on a flat floor surface F.

[0089] Therefore, it is possible to prevent the wheels 105b from lifting off the floor surface F in the state shown in Figure 6. Thus, it is possible to avoid applying a load to the foot frame 103 via the bed movement assist device 1.

[0090] Furthermore, when the bed 100, to which the bed movement assist device 1 is attached, is moved forward, the floor surface F may change from a flat surface to a downward-sloping surface, as shown in Figure 7. In the state shown in Figure 7, wheel 106b is on the flat surface of the floor surface F, and wheel 105b is on the downward-sloping surface of the floor surface F.

[0091] In this state, the height of the support frame 3 in the bed movement assist device 1 is displaced downward. In response, the sliding body 62 of the linear guide mechanism 6 is connected to the bed 100 by the connecting mechanism 7, and therefore moves diagonally upward perpendicular to the downward inclined surface, as shown by the arrow in Figure 7.

[0092] In this way, the sliding body 62 moves upward, in the opposite direction to the downward displacement of the support frame 3. As a result, the distance between the connecting mechanism 7 and the support frame 3 becomes longer than the same distance when the bed moving assist device 1 is moving on a flat floor surface F. Therefore, the loads applied to the wheels 105b of the bed 100 and the drive wheels 4 of the bed moving assist device 1 remain almost unchanged compared to when the bed 100 and the bed moving assist device 1 are moving on a flat floor surface F.

[0093] Therefore, it is possible to prevent the wheel 105b from being strongly pressed against the floor surface F in the state shown in Figure 7. Thus, it is possible to avoid placing an excessive load on the wheel 105b.

[0094] <Effects of the Embodiment> In the bed movement assist device 1, the linear guide mechanism 6 connects the support frame 3 and the connecting mechanism 7 so that they can move relative to each other in the vertical direction.

[0095] As a result, as described above, the connecting mechanism 7 moves in the opposite direction to the displacement of the support frame 3 in response to the vertical displacement of the support frame 3 along with the drive wheels 4 due to fluctuations in the height of the floor surface F. Therefore, regardless of the condition of the floor surface F, it is possible to avoid large changes in the load (load) applied to the foot frame 103 or wheels 105b of the bed 100.

[0096] Furthermore, since the bed relocation assist device 1 is directly connected to the bed 100 via the connection mechanism 7, the overall length of the relocation unit including the bed 100 and the bed relocation assist device 1 can be shortened. Therefore, the bed 100 can be transported into narrow spaces such as elevators.

[0097] Furthermore, the linear guide mechanism 6 can be constructed using a mechanism such as a general-purpose linear guide.

[0098] Furthermore, as described above, the sliding body 62 of the linear guide mechanism 6 is provided so that the connecting mechanism 7 can be moved to a position higher than the height of the upper end of the foot frame 103, and the distance between the support frame 3 and the connecting mechanism 7 changes in response to the displacement of the support frame 3.

[0099] This allows the sliding body 62 to be easily connected to the foot frame 103. Furthermore, the connection mechanism 7 can be moved in the opposite direction to the vertical displacement of the support frame 3 so as not to place a load on the foot frame 103.

[0100] Furthermore, the connection mechanism 7 is provided on the straight guide mechanism 6 and includes an upper hook 71b that holds the upper end of the foot frame 103, and a lower hook 722b that is provided so as to be vertically adjustable and holds the lower end of the foot frame 103.

[0101] As a result, the connection mechanism 7 is connected according to the height of the upper end of the foot frame 103. Therefore, even in beds 100 in which the foot frame 103 can be changed to any height by the lifting mechanism 107, or in beds that do not have a lifting mechanism 107 but have foot frames of different heights, the bed movement assist device 1 can be connected according to the height of the upper end of each foot frame. Thus, a highly versatile bed movement assist device 1 can be provided.

[0102] Furthermore, the drive wheel 4 is a single wheel. This reduces the number of parts. Also, in the case of a two-wheel drive system, if one of the drive wheels is on an inclined surface, torsional displacement occurs in the axle connecting the two wheels. In contrast, with a single drive wheel 4, it is only necessary to absorb the displacement of the connection mechanism 7 by the linear guide mechanism 6 perpendicular to the floor surface F, and no torsional displacement occurs as described above. Therefore, the drive wheel 4 can stably provide propulsion to the bed 100.

[0103] [Embodiment 2] Other embodiments of the present invention are described below. For the sake of clarity, components having the same function as those described in the above embodiments are denoted by the same reference numerals, and their descriptions are not repeated.

[0104] <Configuration of the bed transfer assistance device> Figure 8 is a perspective view showing the configuration of the bed movement assist device 1A. Figure 9 is a perspective view showing other configurations of the bed movement assist device 1A. Figure 10 is a perspective view showing the internal configuration of the bed movement assist device 1A. Figure 11 is a top view showing the configuration of the bed movement assist device 1A. Figure 12 is a side view showing the configuration of the operating mechanism 17 and the state switching mechanism 18 in the bed movement assist device 1A. Figure 13 is a partial cross-sectional view showing a part of the configuration of the slide lock mechanism 220 in the state switching mechanism 18. Figure 14 is a plan view showing the configuration of the plate member 31 in the slide lock mechanism 220.

[0105] As shown in Figures 8 to 11, the bed movement assist device 1A has as its main components a drive wheel 4, a drive mechanism 5, a housing 12, a support frame 14 (support part), a linear guide mechanism 15 (coupling mechanism), a connection mechanism 16 (connection part), an operating mechanism 17, and a state switching mechanism 18. In addition, the bed movement assist device 1A has a controller 13 as a control function, as shown in Figure 5.

[0106] The housing 12 is an exterior body that covers almost the entire bed movement assist device 1A. The housing 12 has a lower section 12a, a middle section 12b, and an upper section 12c. The lower section 12a houses the drive wheels 4 and the drive mechanism 5. The middle section 12b is located above the lower section 12a and houses components such as power supply equipment (not shown). The upper section 12c is located above the middle section 12b and has a pair of handles 121 on its upper surface.

[0107] The support frame 14 is a frame that supports various components that constitute the bed movement assist device 1A. The support frame 14 has a pair of base parts 14a, a main body part 14b, and a drive system housing 14c. The base parts 14a are members that support the main body part 14b, and the drive system housing 14c is positioned between them. The main body part 14b is a part that is mainly formed inside the lower part 12a of the housing 12. The drive wheels 4 and the drive mechanism 5 are arranged in the area surrounded by the main body part 14b. The drive system housing 14c is fixed to the upper part of the main body part 3a. The drive system housing 14c supports the drive wheels 4, just like the drive system housing 3d described above.

[0108] The linear guide mechanism 15 is a mechanism that moves linearly in the vertical direction relative to the support frame 14. The linear guide mechanism 15 has a pair of sliding bodies 151 (fixed parts) and a plurality of nuts 152 (movable parts). The nuts 152 are provided so as to be movable relative to the pair of sliding bodies 151. Note that the sliding bodies 151 may be provided individually rather than in a pair.

[0109] The linear guide mechanism 15 is configured as follows to connect the support frame 14 and the connecting mechanism 16 so that they can move relative to each other in the vertical direction. Specifically, the linear guide mechanism 15 connects the support frame 14 and the connecting mechanism 16 in the direction of travel of the bed movement assist device 1A, i.e., the direction of transport of the bed 100, and moves the connecting mechanism 16 in the opposite direction to the vertical displacement of the support frame 14.

[0110] A pair of sliding bodies 151 are arranged on one end of the base portion 14a on the main body portion 14b of the support frame 14, extending vertically at a distance from each other. Each sliding body 151 is a strip-shaped member having a predetermined length and a predetermined thickness. Each sliding body 151 has a raised ridge (not shown) formed along its entire length.

[0111] Two nuts 152 are provided for each slide body 151, spaced apart in the vertical direction. The nuts 152 have grooves formed along their entire vertical length on both side edges. These grooves loosely fit onto the protrusions of the slide body 151, embracing them. The loose fit of the grooves into the protrusions of the slide body 151 allows the nuts 152 to move in the direction in which the grooves extend. The inner surface of the grooves receives the force from the slide body 151.

[0112] As shown by the arrow in Figure 5, the nut 152 is provided so that the connecting mechanism 16 can be moved to a position higher than the height of the upper end of the foot frame 103 on the bed 100. The sliding body 151 also changes the distance between the support frame 14 and the connecting mechanism 16 in response to the height displacement of the support frame 14.

[0113] The linear guide mechanism 15 is configured such that the slide body 151 is fixed on the main body 14b and the nut 152 moves relative to the slide body 151, but it is not limited to this configuration. Specifically, the linear guide mechanism 15 may function as a slider in which the nut 152 is fixed in a predetermined position and the slide body 151 moves relative to the nut 152.

[0114] Furthermore, the linear guide mechanism 15 is not limited to the above configuration in which the load of the nut 152 is received on the surface of the protrusion on the slide body 151; a mechanism in which the load of the movable part is received by a ball, roller, or the like may also be used.

[0115] The connection mechanism 16 is a mechanism for detachably connecting the bed movement assist device 1A to the bed 100. The connection mechanism 16 has an upper holding mechanism 161 and a lower holding mechanism 162.

[0116] The upper holding mechanism 161 is a mechanism that holds the upper end of the foot frame 103 of the bed 100. The upper holding mechanism 161 has a pair of support members 1611 and a pair of upper hooks 1612 (upper holding parts).

[0117] The pair of support members 1611 are provided on the linear guide mechanism 15 by being fixed to the nut 152, and are members that move together with the nut 152. Each support member 1611 has a main body portion 1611a and a fixing portion 1611b.

[0118] The main body portion 1611a has a vertically extending plate-shaped opposing portion located on the side facing the foot frame 103 of the bed 100, and a vertically extending plate-shaped side portion located on the side of the bed movement assist device 1A. The fixing portion 1611b is provided so as to protrude from the opposing portion of the main body portion 1611a to the opposite side between the pair of support members 1611. A nut 152 is fixed to the fixing portion 1611b.

[0119] A pair of upper hooks 1612 are fixed to the side surface of the support member 1611. The pair of upper hooks 1612 are formed in a hook shape, extending from the upper end of a vertically extending fixing portion fixed to the side surface of the support member 1611, on the opposite side from the upper section 12c of the housing 12, and then bending downwards. With this structure, the pair of upper hooks 1612 engage with the upper end of the foot frame 103 and hold its upper end.

[0120] The lower holding mechanism 162 is a mechanism that holds the lower end of the foot frame 103 of the bed 100. The lower holding mechanism 162 is also provided so that its vertical position can be adjusted. The lower holding mechanism 162 has a pair of connecting plates 1621 and a lifting support member 1622.

[0121] The connecting plate 1621 is a plate-like member having a strip shape with a certain width and a certain length. A pair of connecting plates 1621 are each positioned below a pair of upper hooks 1612. The connecting plates 1621 are provided to connect the upper guide 201, lower guide 202 and slide lock mechanism 220 of the state switching mechanism 18 to the lifting support member 1622 in order to ensure a gap between the lower end of the foot frame 103 and the lifting support member 1622.

[0122] The lifting support member 1622 supports the lower hook 1622c so that it can move up and down relative to the shaft 19, which will be described later, and is a member for positioning the lower hook 1622c in a specified position. The lifting support member 1622 has a pair of connecting parts 1622a, a connecting part 1622b, and a pair of lower hooks 1622c (lower holding parts).

[0123] The pair of connecting parts 1622a have approximately the same size and shape as the connecting plate 1621 so as to contact and connect with the connecting plate 1621. The connecting part 1622b connects the pair of connecting parts 1622a at the lower part of the connecting part 1622a.

[0124] A pair of lower hooks 1622c are provided at intervals at the lower end of the connecting portion 1622b. The pair of lower hooks 1622c protrude slightly downward from the lower end of the connecting portion 1622b, extend to the opposite side from the upper portion 12c of the housing 12, and are formed in a hook shape that bends further upward. With this structure, the lower hooks 1622c engage with the lower end of the foot frame 103 and hold the lower end.

[0125] The operating mechanism 17 is provided for operating the connecting mechanism 16 up and down. As shown in Figures 10 and 12, the operating mechanism 17 has a pair each of a handle 171, a grip 172, a lever 173, a wire 174, a retaining plate 175, and a connecting plate 176.

[0126] The handle 171 is a rod-shaped operating member provided to move the connecting mechanism 16 up and down. As shown in Figure 10, the handle 171 protrudes from both sides of the bed moving assist device 1A and is bent so as to be approximately parallel to the side of the housing 12. The portion of the handle 171 that is approximately parallel to the side of the housing 12 is the grip portion held by the user. The handle 171 is fixed to the upper guide 201 and the lower guide 202 by a connecting plate 176.

[0127] The grip 172 is fitted into the grip portion of the handle 171. The lever 173 is mounted on the handle 171 between the grip portion and the bend portion so as to be rotatable between a non-operating position and an operating position.

[0128] When the lever 173 is not operated by the user, it is biased by a spring so that its tip is in a non-operational position away from the grip 172 (see Figure 12). When the user operates the lever 173 by gripping it against the spring's biasing force, the tip of the handle 171 reaches an operating position close to the grip.

[0129] The wire 174 has an outer wire 174a and an inner wire 174b. The outer wire 174a forms the outer casing of the wire 174 and is routed through the inside of the handle 171 to the slide lock mechanism 220. The inner wire 174b is a wire provided inside the outer wire 174a so as to be movable in its axial direction. The ends of the outer wire 174a and the inner wire 174b are connected to the slide lock mechanism 220. The connection structure of these ends to the slide lock mechanism 220 will be described in detail later.

[0130] The state switching mechanism 18 is a mechanism that switches between a first state and a second state. The first state is a state in which the driving force applied to the handle 171 is applied to both the upper hook 1612 and the lower hook 1622c. The second state is a state in which the driving force is applied only to the lower hook 1622c. The state switching mechanism 18 has a shaft 19, an upper guide 201, a lower guide 202, and a slide lock mechanism 220 (fixing mechanism), each in pairs.

[0131] The shaft 19 moves vertically in conjunction with the nut 152 and is positioned to extend in the direction of movement of the nut 152. Specifically, the shaft 19 is positioned parallel to the sliding body 151 between a position slightly below the upper hook 1612 and a position slightly above the lower end of the side surface of the support member 1611. The shaft 19 is fixed at its upper and lower ends to the side surface of the support member 1611 by fixing members 19a, maintaining a certain distance from the side surface.

[0132] The upper guide 201, lower guide 202, and slide lock mechanism 220 are positioned to pass through the shaft 19 so that they can move up and down along the shaft 19. The upper guide 201 is positioned at the top of the upper guide 201, lower guide 202, and slide lock mechanism 220. The lower guide 202 is positioned at the bottom of the upper guide 201, lower guide 202, and slide lock mechanism 220. The slide lock mechanism 220 is positioned between the upper guide 201 and the lower guide 202. The upper guide 201, lower guide 202, and slide lock mechanism 220 are connected to the connecting portion 1622a of the lifting support member 1622 by bolts, with a connecting plate 1621 in between.

[0133] The upper guide 201 and the lower guide 202 have holes through which the shaft 19 is inserted, with an inner diameter slightly larger than the diameter of the shaft 19, so that they can slide relative to the shaft 19.

[0134] The slide lock mechanism 220 is integrated with the lower hook 1622c and is fixed to the shaft 19 when switched to the first state, and not fixed to the shaft 19 when switched to the second state. The slide lock mechanism 220 has a case 203 and a clamper 24 as shown in Figure 13. A pair of clampers 24 are provided and are built into the case 203 except for the plate member 31. Note that the clamper 24 shown in Figure 13 represents the clamper 24 provided on the lower side. The clamper 24 provided on the upper side is positioned so as to be oriented in the opposite direction to the clamper 24 on the lower side.

[0135] The clamper 24 includes a base 25, a retainer 26, an outer ring 27, a spring holder 28, a guide roller 29, a compression coil spring 30, and a plate member 31.

[0136] The base 25 is provided in common for a pair of clamps 24 and supports the pair of clamps 24. The base 25 is also connected to the case 203. A shaft 19 is inserted through the center of the base 25 so that it can move in its axial direction.

[0137] The retainer 26 is a cylindrical member positioned on the base 25 and has an annular void 26a near its upper end. The void 26a is divided into multiple regions by having parts that connect vertically at multiple locations.

[0138] The outer ring 27 is a cylindrical member having an inner diameter larger than the outer diameter of the retainer 26, and is positioned to cover a part of the retainer 26. The inner wall portion of the outer ring 27 has an inner diameter smaller at the first opening near the base 25 than at the inner diameter of the intermediate portion, and a tapered surface 27a is formed between the first opening and the intermediate portion.

[0139] The spring retainer 28 is a disc-shaped member fitted into the inner wall surface of the second opening of the outer ring 27, which is furthest from the base 25. The spring retainer 28 has a hole in its center through which the shaft 19 is inserted.

[0140] Multiple guide rollers 29 are provided, with one placed in each of the regions partitioned as described above within the gap 26a of the retainer 26. The guide rollers 29 are shaped like bales and are formed to be constricted in the middle so as to contact the outer surface of the shaft 19.

[0141] The compression coil spring 30 is positioned between the open end of the retainer 26 and the spring support 28.

[0142] The plate member 31 is positioned so as to partially contact the end face of the outer ring 27 on the second opening side, which is biased by the compression coil spring 30. As shown in Figure 14, the plate member 31 has a bent plate 31a, a circular hole 31b, a hinge 31c, and a wire hole 31d.

[0143] The bent plate 31a is a rectangular plate member formed to bend at an angle close to 180° but less than 180° in the center. A circular hole 31b is provided in the center of the bent plate 31a through which the shaft 19 is inserted. A pair of hinges 31c are provided at the positions of two adjacent apex corners of the bent plate 31a so that the plate member 31 is mounted to be rotatably supported relative to the case 203. The hinges 31c have a built-in V-spring and are biased to the position shown in Figure 13 when no external force is applied. The wire hole 31d is a hole through which the inner wire 174b is inserted.

[0144] In the slide lock mechanism 220, an inner wire 174b is inserted through the wire hole 31d of the plate member 31 of the upper clamper 24. The tip of the outer wire 174a is in contact with the area around the wire hole 31d of the bent plate 31a of the upper clamper 24. An inner wire 174b is inserted through the wire hole 31d of the plate member 31 of the lower clamper 24. The tip of the inner wire 174b is fixed by a retainer 175 to prevent it from coming out of the wire hole 31d.

[0145] In the slide lock mechanism 220 configured as described above, when the lever 173 is not operated, the plate member 31 is in a standby position at the lower clamper 24, biased by the V-spring of the hinge 31c, as shown in Figure 13. In this state, the compression coil spring 30 extends, pushing down the spring retainer 28 as shown by the dashed line in Figure 13. As a result, in the slide lock mechanism 220, the tapered surface 27a of the outer ring 27 is lowered, and the guide roller 29 is pushed towards the shaft 19 by the tapered surface 27a. As a result, the guide roller 29 presses against the shaft 19, clamping the outer ring 27 to the shaft 19. The upper clamper 24, although oriented in the opposite direction to the lower clamper 24, operates similarly to the lower clamper 24, clamping the outer ring 27 to the shaft 19.

[0146] The slide lock mechanism 220, through this operation using two clamps 24, can firmly lock the lifting support member 1622 to the shaft 19.

[0147] When the lever 173 is gripped, the tip of the inner wire 174b moves upward. This causes the retaining clip 175 at the tip of the inner wire 174b to move the movable end of the plate member 31 upward against the biasing force of the V-spring of the hinge 31c. As a result, the outer ring 27 is pushed up by the plate member 31 and moves upward in the lower clamper 24. Consequently, as shown by the solid line in Figure 13, when the tapered surface 27a of the outer ring 27 rises against the biasing force of the compression coil spring 30, the guide roller 29 is no longer pressed by the tapered surface 27a. As a result, the clamped state of the shaft 19 is released.

[0148] Furthermore, in the operating state, the tip of the outer wire 174a moves the movable end of the plate member 31 in the upper clamper 24 downward, as shown in Figure 12. As a result, in the upper clamper 24, as the plate member 31 moves downward, the tapered surface 27a of the outer ring 27 goes down, and the guide roller 29 is no longer pressed by the tapered surface 27a, thereby releasing the clamped state of the shaft 19.

[0149] The slide lock mechanism 220 allows the clamped state of the two clampers 24 to be released by operating the lever 173.

[0150] <Operation of the bed transfer assist device> Figure 15 shows the procedure for connecting the bed movement assist device 1A to the bed.

[0151] (1) Lifting process As shown in Figure 15, first, the user raises the connecting mechanism 16 by gripping and pulling up the grip 172. In this state, since the lever 173 is not operated, the lower holding mechanism 162 is locked to the shaft 19 by the slide lock mechanism 220 of the state switching mechanism 18. As a result, the connecting mechanism 16, with the upper holding mechanism 161 and the lower holding mechanism 162 working together, moves upward as the nut 152 moves upward in the linear guide mechanism 15. At this point, the user moves the connecting mechanism 16 until the upper hook 1612 reaches a position higher than the height of the upper end of the foot frame 103.

[0152] (2) Moving process Next, the user moves the bed relocation assist device 1A by pushing it towards the bed 100 while holding the grip 172. At this time, the user moves the bed relocation assist device 1A to a position where the upper hook 1612 reaches above the upper end of the foot frame 103.

[0153] (3) Push-down process Next, the user lowers the connecting mechanism 16 by pushing down on the grip 172 while holding it. At this time, the user pushes down the handle 171 until the upper hook 1612 engages with the upper end of the foot frame 103.

[0154] (4) Operation and lifting process Next, the user raises the connecting mechanism 16 by pulling up the handle 171 while gripping and operating the lever 173. In this state, because the lever 173 has been operated, the slide lock mechanism 220 of the state switching mechanism 18 releases the lock of the lower holding mechanism 162 to the shaft 19. As a result, the lower holding mechanism 162 can move along the shaft 19 independently of the upper holding mechanism 161. When the handle 171 is pulled up in this state, the nut 152 in the linear guide mechanism 15 moves upward, causing the lower holding mechanism 162 to move upward. At this time, the user moves the lower holding mechanism 162 until it reaches a position where the lower hook 1622c engages with the lower end of the foot frame 103.

[0155] <Effects of the Embodiment> In the bed movement assist device 1A, the linear guide mechanism 15 connects the support frame 14 and the connecting mechanism 16 so that they can move relative to each other in the vertical direction.

[0156] As a result, similar to the bed movement assist device 1 according to Embodiment 1, the connecting mechanism 16 moves in the opposite direction to the displacement direction of the support frame 14 in response to the vertical displacement of the support frame 14 together with the drive wheels 4 due to fluctuations in the height of the floor surface F. Therefore, regardless of the state of the floor surface F, it is possible to avoid large changes in the load (load) applied to the foot frame 103 or wheels 105b of the bed 100.

[0157] Furthermore, since the bed relocation assist device 1A is directly connected to the bed 100 via the connection mechanism 16, the overall length of the relocation unit including the bed 100 and the bed relocation assist device 1A can be shortened. Therefore, the bed 100 can be transported into narrow spaces such as elevators.

[0158] Furthermore, the linear guide mechanism 15 can be constructed using a mechanism such as a general-purpose linear guide.

[0159] Furthermore, as described above, the nut 152 of the linear guide mechanism 15 is provided so that the connecting mechanism 16 can be moved to a position higher than the height of the upper end of the foot frame 103, and the distance between the support frame 14 and the connecting mechanism 16 changes in response to the displacement of the support frame 14. This allows the nut 152 to be easily connected to the foot frame 103. In addition, the connecting mechanism 16 can be moved in the opposite direction to the vertical displacement of the support frame 14 so as not to put a load on the foot frame 103.

[0160] Furthermore, the connecting mechanism 16 is provided on the linear guide mechanism 15 and includes an upper hook 1612 that holds the upper end of the foot frame 103, and a lower hook 1622c that is adjustable vertically and holds the lower end of the foot frame 103.

[0161] As a result, the connection mechanism 16 is connected according to the height of the upper end of the foot frame 103. Therefore, even in beds 100 in which the foot frame 103 can be changed to any height by the lifting mechanism 107, or in beds that do not have a lifting mechanism 107 but have foot frames of different heights, the bed movement assist device 1A can be connected according to the height of the upper end of each foot frame. Thus, a highly versatile bed movement assist device 1A can be provided.

[0162] Furthermore, the first and second states can be switched by operating the lever 173 while holding the handle 171. This eliminates the need for the user to release their hands from the handle and switch to another operating part when moving the upper holding mechanism 161 and the lower holding mechanism 162 up and down, or when moving only the lower holding mechanism 162. This simplifies the work procedure and reduces the amount of work required. Therefore, when the height of the connection point differs for each bed 100, the heights of the upper holding mechanism 161 and the lower holding mechanism 162 can be easily adjusted to connect to the bed 100.

[0163] Furthermore, when the lower holding mechanism 162 is switched to the first state, it moves up and down together with the upper holding mechanism 161 and the shaft 19 due to the movement of the nut 152, while when the lower holding mechanism 162 is switched to the second state, it can move up and down along the shaft 19. This allows the lower holding mechanism 162 to move independently of the upper holding mechanism 161.

[0164] [Additional Notes] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Furthermore, embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also included within the technical scope of the present invention. [Explanation of symbols]

[0165] 1.1A Bed transfer assist device 4 drive wheels 3.14 Support frame (support part) 6.15 Straight guide mechanism (coupling mechanism) 7.16 Connection mechanism (connection part) 18. State switching mechanism 19 shafts 61. Nut (fixing part) 62. Sliding body (movable part) 71b,1612 Upper hook (upper holding part) 722b, 1622c Lower hook (lower holding part) 100 beds 103 Foot frame (connected part) 151 Sliding body (fixing part) 152 Nut (movable part) 171 Handle 173 Lever 220 Slide lock mechanism (fixing mechanism)

Claims

1. A bed movement assist device that assists in moving a bed, Drive wheels and A support portion that supports the aforementioned drive wheel, A connecting part that can be detachably connected to the aforementioned bed, A bed movement assist device comprising a connecting mechanism that connects the support portion and the connecting portion so that they can move relative to each other in the vertical direction.

2. The bed movement assist device according to claim 1, wherein the connecting mechanism comprises a linear guide mechanism having a fixed part fixed to the support part and a movable part that is movable relative to the fixed part.

3. The bed movement assist device according to claim 2, wherein the movable part is provided so as to be able to move the connecting part to a position higher than the height of the upper end of the connected part on the bed, and changes the distance between the support part and the connecting part in response to the displacement of the support part.

4. The bed movement assist device according to claim 3, wherein the connecting portion is provided on the linear guide mechanism and includes an upper holding portion that holds the upper end of the connected portion on the bed, and a lower holding portion that is vertically adjustable and holds the lower end of the connected portion.

5. A handle for moving the aforementioned connecting part up and down, A state switching mechanism that switches between a first state in which both the upper and lower holding parts are moved up and down by the handle, and a second state in which only the lower holding part is moved up and down by the handle. The bed moving assist device according to claim 4, further comprising a lever provided on the handle for operating the switching between the first state and the second state by the state switching mechanism.

6. The aforementioned state switching mechanism is: A shaft that moves vertically in conjunction with the movable part and is arranged in the direction of movement of the movable part, The bed movement assist device according to claim 5, further comprising a fixing mechanism provided integrally with the lower holding portion, which is fixed to the shaft when switched to the first state and not fixed to the shaft when switched to the second state.

7. The bed moving assist device according to any one of claims 1 to 6, wherein the drive wheel is a single wheel.

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