JP2021194191A - Electric bed - Google Patents

Abstract

To provide an electric bed that can easily reduce an occurrence of a problem by being caught.SOLUTION: An electric bed 1 includes: a bottom 4; an actuator A for changing the posture or the height of the bottom 4; a receiving member 66 for receiving a downward load of the bottom 4 at the lowest position in a movable range of the bottom 4; a hand switch 8 for receiving an operation instruction of a user; a control part 7 for controlling an operation of the actuator A according to the operation instruction received by the hand switch 8; and a ratchet mechanism for prohibiting a downward movement to change the posture or the height of the bottom 4 downward by the actuator A when the load applied to the actuator A does not satisfy a predetermined reference load.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electric bed with an actuator.

Conventionally, electric beds have been known in which the height of the bottom that supports the user's body can be changed by the driving force of the actuator, and the angle of the bottom can be changed to raise the back or raise the legs. In such an electric bed, there is known one that prevents a human body or a foreign substance from being caught between the bottom and the frame when the bottom is lowered (see, for example, Patent Document 1).

The electric bed described in Patent Document 1 is sandwiched by reading out the current operation profile data at a predetermined movement position of the bed movable portion calculated by the calculation unit and the corresponding basic operation profile data from the storage unit and comparing the predetermined inclinations. It is equipped with a microcontroller that detects the presence or absence of.

Japanese Unexamined Patent Publication No. 2009-2474226

However, the electric bed described in Patent Document 1 includes an ammeter that detects the current flowing through the actuator, a storage unit that stores basic operation profile data obtained in advance from the current flowing through the actuator in a no-load state, and a movable bed unit. A microcontroller that calculates the current operation profile data at the predetermined movement position is required. Therefore, there was a need to simplify the configuration for preventing pinching.

An object of the present invention is to provide an electric bed in which it is easy to reduce the possibility of problems caused by pinching.

The electric bed according to the present invention includes a bottom, an actuator that changes the posture or height of the bottom, a receiving member that receives a downward load of the bottom at a lower limit position in the movable range of the bottom, and a user. An operation unit that receives an operation instruction, a control unit that controls the operation of the actuator in response to an operation instruction received by the operation unit, and when the load applied to the actuator does not reach a predetermined reference load, the actuator is used. It is provided with a prohibition mechanism for prohibiting a downward movement that changes the posture or height of the bottom downward.

According to this configuration, since the actuator changes the posture or height of the bottom, the load of the bottom is usually applied to the actuator. However, if the bottom is pinched in the process of moving the bottom downward, a load is applied to the pinched human body or an object, so that the load applied to the actuator is reduced. When the load applied to the actuator is less than the reference load, the prohibition mechanism prohibits the downward operation of the bottom, so that the possibility that the driving force of the actuator acts as a pinching force is reduced. Therefore, it is easy to reduce the possibility of problems due to pinching.

Further, the actuator includes a motor, a telescopic rod connected to the bottom, and a gear mechanism for expanding and contracting the telescopic rod by the rotational driving force of the motor, and when the telescopic rod contracts, the downward operation is performed. When the telescopic rod is extended, the bottom is changed or raised upward, and the prohibition mechanism idles the gear mechanism when the load in the direction of contracting the telescopic rod is less than the reference load. It is preferable that the ratchet mechanism prohibits the downward operation by allowing the ratchet mechanism.

According to this configuration, since the ratchet mechanism functions as a prohibition mechanism, it is easy to configure the prohibition mechanism.

Further, in the case where the downward operation of the actuator is prohibited and the bottom is located above the lower limit position during the descent period in which the operation instruction for the downward operation is received by the operation unit. When the actuator is used to perform an upward motion of changing or raising the bottom upward, the downward motion of the actuator is prohibited during the descending period, and the bottom is located at the lower limit position. It is preferable not to cause the actuator to perform the upward operation.

If the downward movement of the actuator is prohibited and the bottom is located above the lower limit position, it is considered that pinching may have occurred. In this case, the posture of the bottom can be changed or raised upward to release the pinching, so that the safety is improved. On the other hand, when the bottom is located at the lower limit position, the load of the bottom is received by the receiving member, and when the load applied to the actuator falls below the reference load, the downward operation of the actuator is prohibited even though pinching has not occurred. To. In this case, if the posture is changed or raised upward, the bottom cannot be maintained at the lower limit position. Therefore, when the downward movement of the actuator is prohibited and the bottom is located at the lower limit position, the bottom can be maintained at the lower limit position by not causing the actuator to perform the upward movement.

An electric bed having such a configuration can easily reduce the possibility of problems due to pinching.

It is a perspective view which shows the structure of the electric bed which concerns on one Embodiment of this invention. FIG. 3 is a perspective view showing a state in which the elevating frame of the electric bed shown in FIG. 1 is raised and the bottom, headboard, and footboard are removed. It is a front view of the electric bed shown in FIG. It is a front view of the electric bed shown in FIG. It is a block diagram which shows an example of the electric structure of the electric bed shown in FIG. It is an external view which shows an example of a hand switch. It is a flowchart which shows an example of the operation of the electric bed shown in FIG.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. It should be noted that the configurations with the same reference numerals in the respective figures indicate that they are the same configurations, and the description thereof will be omitted. In the present specification, the arrow shown in each figure indicates the direction of the electric bed 1. FIG. 1 is a perspective view showing a configuration of an electric bed 1 according to an embodiment of the present invention.

As shown in FIG. 1, the electric bed 1 is formed in a substantially rectangular shape having a longitudinal direction in the front-rear direction in a plan view. The electric bed 1 is roughly a base unit 2 mounted on a floor surface, an elevating frame 3 movably connected to the base unit 2, a bottom 4 attached to the upper surface of the elevating frame 3, and an elevating frame 3. A headboard 51 to be assembled to the front end of the frame 3 and a footboard 52 to be attached to the rear end of the elevating frame 3 are provided as main components.

The bottom 4 includes a head bottom 41, a back bottom 42, a seat bottom 43, a knee bottom 44, and a leg bottom 45. The head bottom 41 is placed at a position that supports the user's head, the back bottom 42 is placed at a position that supports the user's back, the seat bottom 43 is placed at a position that supports the user's waist, and the knee bottom 44 is used. The leg bottom 45 is arranged at a position that supports the user's knee, and the leg bottom 45 is arranged at a position that supports the user's leg.

The user of the electric bed 1 uses the electric bed 1 by laying a mattress (not shown) on the upper surface of the bottom 4 and lying on the mattress with the head on the front side and the feet on the back side.

FIG. 2 is a perspective view showing a state in which the elevating frame 3 of the electric bed 1 shown in FIG. 1 is raised and the bottom 4, the headboard 51, and the footboard 52 are removed. The electric bed 1 includes actuators A1, A2, A3, A4, and a control box C for controlling the drive thereof. The actuators A1, A2, A3, and A4 include a telescopic rod R and a drive unit M including a motor and a gear mechanism for expanding and contracting the telescopic rod R.

The base unit 2 is a base portion that directly or indirectly supports all the components of the electric bed 1, and is formed in a rectangular shape having a longitudinal direction in the front-rear direction in a plan view. As shown in FIG. 2, the base unit 2 includes support frames 21 and 21 having an axial direction in the front-rear direction on the left and right.

Leg seats 22 mounted on the floor surface are attached to both front and rear ends of the support frames 21 and 21. Between the support frames 21 and 21, a support pillar 23 is bridged to the front portion and a support pillar 24 is bridged to the rear portion in the left-right direction. As a result, the support frames 21 and 21 are connected, and the base unit 2 is configured as a strong frame by the support frames 21 and 21 and the support columns 23 and 24.

Further, between the support frames 21 and 21, in the region between the support pillars 23 and the support pillars 24, the support pillars 25 slidable in the front-rear direction are bridged in the left-right direction. Rollers (not shown) are attached to both ends of the support column 25. The guide members 211 provided inside the support frames 21 and 21 guide the rollers at both ends of the support pillar 25 so that the support pillar 25 can slide in the front-rear direction.

The elevating frame 3 is roughly a rectangular frame having a longitudinal direction in the front-rear direction in a plan view. The elevating frame 3 is movably connected to the base unit 2 by a pair of left and right X-shaped link mechanisms 6. The X-shaped link mechanism 6 is configured such that a link 61 and a link 62 having the same length are rotatably connected to each other around a shaft 63 extending in the left-right direction at a substantially central position.

The lower ends of the pair of links 61 are swingably connected to the support column 23 around an axis extending in the left-right direction. A roller (not shown) is attached to the upper end of the pair of links 61. The rollers of the pair of links 61 are guided by the guide members 31, 31 attached to the elevating frame 3, so that the upper ends of the pair of links 61 are slidably connected to the elevating frame 3 in the front-rear direction. There is.

The lower ends of the pair of links 62 are connected to the support columns 25. The upper ends of the pair of links 62 are swingably connected to the elevating frame 3 around an axis extending in the left-right direction. A connecting rod 64 is bridged between the pair of links 61 at a position above the shaft 63.

A connecting rod 27 is bridged between the support frames 21 and 21. The drive unit M of the actuator A1 is swingably connected to the substantially central portion of the connecting rod 27. A bracket 65 extending in the radial direction is attached to a substantially central portion of the connecting rod 64. The tip of the telescopic rod R of the actuator A1 is swingably connected to the tip of the bracket 65 around an axis extending in the left-right direction.

As a result, when the telescopic rod R of the actuator A1 extends, the X-shaped link mechanism 6 extends in the vertical direction and the elevating frame 3 rises, and when the telescopic rod R of the actuator A1 contracts, the X-shaped link mechanism 6 extends in the vertical direction. The elevating frame 3 contracts and descends.

FIG. 3 is a front view of the electric bed 1 shown in FIG. FIG. 3 shows a state in which the bottom 4 is attached. In the links 61 and 62 of the X-shaped link mechanism 6, the receiving member 66 is attached to the lower surface of the links 61 and 62 above the shaft 63. The receiving member 66 protrudes in the left-right direction, and when the X-shaped link mechanism 6 contracts, the receiving member 66 of the link 61 interferes with the link 62, and the receiving member 66 of the link 62 interferes with the link 61. ing. The receiving member 66 is made of an elastic member such as rubber.

FIG. 4 is a front view of the electric bed 1 shown in FIG. When the X-shaped link mechanism 6 contracts in the vertical direction and the elevating frame 3 descends, the receiving member 66 is sandwiched between the links 61 and 62, the X-shaped link mechanism 6 does not contract any more, and the elevating frame 3 does not descend. The position of the bottom 4 at this time is the lower limit position of the movable range of the height of the bottom 4. At this time, the load of the bottom 4 is received by the receiving member 66.

The elevating frame 3 includes a movable frame 411 that supports the head bottom 41, a movable frame 421 that supports the back bottom 42, a movable frame 441 that supports the knee bottom 44, and a movable frame 451 that supports the leg bottom 45. It is connected. A seat bottom 43 is fixedly attached to the elevating frame 3 between the movable frame 421 and the movable frame 441.

The movable frame 421 is connected to the elevating frame 3 so as to be swingable around an axis extending in the left-right direction with its rear end as a fulcrum. The drive unit M of the actuator A2 is swingably connected to the elevating frame 3 around an axis extending in the left-right direction. The tip of the telescopic rod R of the actuator A2 is connected to the movable frame 421 via the link mechanism 422.

The front end of the movable frame 421 and the rear end of the movable frame 411 are oscillatedly connected to each other by a hinge 412 around an axis extending in the left-right direction. The drive unit M of the actuator A3 is swingably connected to the movable frame 421 about an axis extending in the left-right direction. The tip of the telescopic rod R of the actuator A3 is connected to the movable frame 411 via the bracket 413.

As a result, when the telescopic rod R of the actuator A2 is extended, the movable frame 421 rotates so as to stand up and changes its posture upward, and the movable frame 411 and the actuator A3 move upward in conjunction with the posture change of the movable frame 421. Moving. When the telescopic rod R of the actuator A2 contracts, the movable frame 421 rotates so as to fall and changes its posture downward, and the movable frame 411 and the actuator A3 move downward in conjunction with the posture change of the movable frame 421.

Since the back bottom 42 is attached to the movable frame 421 and the head bottom 41 is attached to the movable frame 411, when the telescopic rod R of the actuator A2 is extended, the head bottom 41 and the back bottom 42 are interlocked and rise upward. When the telescopic rod R of the actuator A2 contracts, the head bottom 41 and the back bottom 42 are interlocked and fall downward.

When the back bottom 42 changes its posture downward and becomes horizontal, the front end of the movable frame 421 or the link mechanism 422 or the like interferes with the elevating frame 3, and the back bottom 42 cannot change its posture further downward. The position of the back bottom 42 at this time is the lower limit position of the movable range of the posture of the back bottom 42. At this time, the loads of the back bottom 42 and the head bottom 41 are received by the elevating frame 3. The elevating frame 3 corresponds to an example of a receiving member for the back bottom 42.

When the telescopic rod R of the actuator A3 is extended, the movable frame 411 changes its posture upward and the head bottom 41 rises. When the telescopic rod R of the actuator A3 contracts, the movable frame 411 changes its posture downward, and the head bottom 41 approaches flat with respect to the back bottom 42.

The movable range of the hinge 412 is limited to the posture in which the movable frame 411 and the movable frame 421 are flat, that is, the flat posture in which the head bottom 41 and the back bottom 42 are flat, and the head bottom 41 and the back bottom 42. The hinge 412 bends in the direction in which the bottom angle formed on the upper side becomes smaller than the flat posture, but the hinge 412 locks so as not to bend in the direction in which the bottom angle becomes larger than the flat posture.

When the head bottom 41 and the back bottom 42 are in a flat posture and the hinge 412 is locked, the position of the head bottom 41 at this time becomes the lower limit position of the movable range of the posture of the head bottom 41. At this time, the load of the head bottom 41 is received by the hinge 412. The hinge 412 corresponds to an example of a receiving member for the head bottom 41.

The movable frame 441 is connected to the elevating frame 3 so as to be swingable around an axis extending in the left-right direction with its front end as a fulcrum. The rear end of the movable frame 441 is swingably connected to the front end of the movable frame 451 around an axis extending in the left-right direction by a hinge 442. The drive unit M of the actuator A4 is swingably connected to the elevating frame 3 around an axis extending in the left-right direction. The tip of the telescopic rod R of the actuator A4 is connected to the movable frame 441 via the link mechanism 443.

As a result, when the telescopic rod R of the actuator A4 is extended, the movable frame 441 rotates so as to stand up and changes its posture upward, and the front end of the movable frame 451 is lifted in conjunction with the posture change of the movable frame 441. On the other hand, when the telescopic rod R of the actuator A4 contracts, the movable frame 441 rotates so as to approach horizontal and changes its posture downward, and the front end of the movable frame 451 descends in conjunction with the posture change of the movable frame 441. ..

A knee bottom 44 is attached to the movable frame 441, and a leg bottom 45 is attached to the movable frame 451. Therefore, when the telescopic rod R of the actuator A4 is extended, the knee bottom 44 and the leg bottom 45 have the hinge 442 at the top. When the telescopic rod R of the actuator A4 contracts, the hinge 442 descends, and the knee bottom 44 and the leg bottom 45 approach each other horizontally.

When the hinge 442 descends and the knee bottom 44 and the leg bottom 45 change their postures downward and become horizontal, the rear end of the movable frame 441, the front end of the movable frame 451 or the hinge 442 interferes with the elevating frame 3. The knee bottom 44 and the leg bottom 45 cannot change their postures any more. The positions of the knee bottom 44 and the leg bottom 45 at this time are the lower limit positions of the movable range of the postures of the knee bottom 44 and the leg bottom 45. At this time, the loads of the knee bottom 44 and the leg bottom 45 are received by the elevating frame 3. The elevating frame 3 corresponds to an example of a receiving member for the knee bottom 44 and the leg bottom 45.

Hereinafter, the operation of raising the bottom 4 by the actuator A1 and the operation of changing the postures of the head bottom 41, the back bottom 42, the knee bottom 44, and the leg bottom 45 by the actuators A2, A3, and A4 are collectively referred to as an upward operation. The operation of lowering the bottom 4 by the actuator A1 and the operation of changing the posture of the head bottom 41, the back bottom 42, the knee bottom 44, and the leg bottom 45 downward by the actuators A2, A3, and A4 are collectively referred to as downward. Called operation.

FIG. 5 is a block diagram showing an example of the electrical configuration of the electric bed 1 shown in FIG. As shown in FIG. 5, the electric bed 1 includes actuators A1, A2, A3, A4, control modules A1C, A2C, A3C, A4C, a hand switch 8, and a control unit 7. Hereinafter, the actuators A1, A2, A3, and A4 are collectively referred to as an actuator A, and the control modules A1C, A2C, A3C, and A4C are collectively referred to as a control module AC.

The actuators A1, A2, A3, and A4 are connected to the control unit 7 via the control modules A1C, A2C, A3C, and A4C. The control module AC expands and contracts the actuator A in response to a control signal from the control unit 7.

The telescopic rod R of the actuator A is, for example, a spline shaft. The gear mechanism (not shown) of the actuator A expands and contracts the telescopic rod R by rotating the telescopic rod R around the axis by the rotational driving force of the motor.

The actuator A is provided with a ratchet mechanism (claw wheel) that prohibits downward operation by idling the above-mentioned gear mechanism when the load in the direction of contracting the telescopic rod R is less than a predetermined reference load. Such a ratchet mechanism corresponds to an example of a prohibition mechanism.

Although the example in which the actuator A has a built-in ratchet mechanism is shown, the ratchet mechanism (prohibition mechanism) may be provided outside the actuator A.

Further, the actuator A includes a rotation detection sensor (not shown) that detects the rotation of the telescopic rod R. When the rotation detection sensor detects the rotation of the telescopic rod R, a signal indicating the rotation is output to the control module AC. As the rotation detection sensor, for example, a Hall element can be used. For example, the rotation of the telescopic rod R can be detected by attaching a magnet to a predetermined position on the outer circumference of the telescopic rod R and detecting the magnetic force of the magnet using a Hall element.

The control module AC calculates the extended length of the telescopic rod R, that is, the stroke position, based on the signal indicating the rotation of the telescopic rod R output from the actuator A, and the control unit 7 calculates the signal indicating the stroke position. Output to. Further, the control module AC detects that the gear mechanism is idled by the ratchet mechanism and the downward operation is prohibited, and outputs a signal indicating that the downward operation is prohibited to the control unit 7.

The control module AC outputs, for example, a signal indicating the rotation of the telescopic rod R from the actuator A during a period in which the control module AC outputs a control signal for a downward operation for contracting the telescopic rod R to the actuator A. If it is no longer possible, it can be determined that the downward movement is prohibited.

As the actuator A having the above-mentioned function, for example, a linear actuator LA40 manufactured by LINAK can be used, and as the control module AC having the above-mentioned function, for example, the control box C061 manufactured by LINAK can be used. ..

The actuator A may be provided with a prohibiting mechanism for prohibiting downward operation when the load in the direction of contracting the telescopic rod R is less than a predetermined reference load, and the actuator A is limited to a linear actuator manufactured by LINAK. However, the prohibition mechanism is not limited to the ratchet mechanism.

Further, the control module AC is not limited to the control box manufactured by LINAK, and the actuator A or the control unit 7 may have the functions of the control module AC.

FIG. 6 is an external view showing an example of the hand switch 8. The hand switch 8 includes a height lowering button 80D, a height raising button 80U, a head lowering button 81D, a head raising button 81U, a back lowering button 82D, a back raising button 82U, a foot lowering button 83D, a foot raising button 83U, and a power switch 86. , And a display unit 87.

The display unit 87 is composed of, for example, a liquid crystal display or the like, and displays the height, posture, and the like of each bottom 4. The hand switch 8 is an operation unit that receives an operation instruction from the user. The hand switch 8 outputs a signal indicating the received instruction to the control unit 7.

The height lowering button 80D receives an operation instruction for the downward operation of the entire bottom 4, and the height up button 80U receives an operation instruction for the upward operation of the entire bottom 4. The head-down button 81D and the back-down button 82D receive operation instructions for downward movement of the head bottom 41 and the back bottom 42, respectively. The head-raising button 81U and the back-raising button 82U receive operation instructions for upward movement of the head bottom 41 and the back bottom 42, respectively. The foot lowering button 83D receives operation instructions for downward movement of the knee bottom 44 and the leg bottom 45. The foot-raising button 83U receives operation instructions for upward movement of the knee bottom 44 and the leg bottom 45.

The control unit 7 is housed in the control box C. The control unit 7 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a RAM (Random Access Memory) that temporarily stores data, a non-volatile storage unit that stores a predetermined control program, and the like. It is configured to be equipped with peripheral circuits and the like.

The control unit 7 controls the operation of the actuator A according to the operation instruction received by the hand switch 8.

Further, in the control unit 7, the bottom 4 is positioned above the lower limit position during the descending period in which the operation instruction for the downward operation is received by the hand switch 8, and the downward operation of the actuator A is prohibited. When this is done, the actuator A is made to perform an upward operation.

Further, in the control unit 7, the bottom 4 is located at the lower limit position during the descending period in which the operation instruction for the downward operation is received by the hand switch 8, and the downward operation of the actuator A is prohibited. When, the instruction to cause the actuator A to execute the downward operation is continued.

Next, the operation of the electric bed 1 configured as described above will be described. FIG. 7 is a flowchart showing an example of the operation of the electric bed 1 shown in FIG. Hereinafter, an operation of lowering the bottom 4 from a state in which the elevating frame 3 is raised and the bottom 4 is in a high position as shown in FIG. 3 will be described as an example.

First, when the user presses the height lowering button 80D, the hand switch 8 receives an operation instruction for the downward operation of the entire bottom 4 (step S1), and the hand switch 8 moves downward to the control unit 7 and the entire bottom 4 is downward. Operation instructions are output. Hereinafter, it is assumed that the height lowering button 80D is held while being pressed.

Next, the control unit 7 instructs the actuator A1 corresponding to the height of the entire bottom 4 to operate downward via the control module A1C, and contracts the telescopic rod R (step S2). The control unit 7 stops the operation of the actuator A when the button is no longer pressed.

When the telescopic rod R contracts and the X-shaped link mechanism 6 contracts, the bottom 4 is lowered together with the elevating frame 3, and a downward operation is executed. During the period during which the downward operation is being executed, the control unit 7 monitors the signal from the control module A1C indicating the prohibition of the downward operation (step S3), and if the downward operation is not prohibited (NO in step S3). , The downward operation by the actuator A1 is continued (steps S2 and S3).

On the other hand, when the gear mechanism of the actuator A1 is idled by the ratchet mechanism and the downward operation of the actuator A1 is prohibited, the control module A1C detects that the downward operation is prohibited, and the control module A1C moves downward to the control unit 7. A signal indicating the prohibition of operation is output (YES in step S3).

Then, the control unit 7 refers to the signal from the control module A1C indicating the stroke position of the telescopic rod R of the actuator A1 and confirms whether or not the bottom 4 is above the lower limit position (step S4). If the bottom 4 is above the lower limit position (YES in step S4), there is a possibility that a human body or a foreign object is caught under the elevating frame 3 in the process of descending.

If a human body or a foreign object is caught under the elevating frame 3 in the process of descending, a load such as the elevating frame 3 is applied to the pinched human body or the foreign substance. When a load such as the elevating frame 3 is applied to the pinched human body or foreign matter, the load applied to the telescopic rod R of the actuator A1 is reduced. When the load applied to the telescopic rod R is less than the reference load, the gear mechanism of the actuator A1 is idled by the ratchet mechanism, and the downward operation of the actuator A1 is prohibited.

As a result, the possibility that the driving force of the actuator A1 is applied to the human body or foreign matter sandwiched under the elevating frame 3 is reduced, so that the safety is improved. Therefore, according to the electric bed 1, it is easy to reduce the possibility of problems due to pinching.

At this time, when the downward operation of the actuator A1 is prohibited by the ratchet mechanism, the control module A1C detects that the downward operation is prohibited, and a signal indicating the prohibition of the downward operation is output from the control module A1C to the control unit 7. (YES in step S3). Therefore, if the downward movement is prohibited (YES in step S3) and the bottom 4 is above the lower limit position (YES in step S4), it is possible that a human body or a foreign object is caught under the elevating frame 3 in the process of descending. There is sex.

Therefore, when the bottom 4 is above the lower limit position (YES in step S4), the control unit 7 causes the actuator A1 to execute an upward operation and raises the elevating frame 3 (step S5).

As a result, even if a human body or a foreign object is sandwiched under the elevating frame 3, the sandwiched human body or the foreign substance is released, so that the safety is further improved.

On the other hand, when the bottom 4 is located at the lower limit position in step S4 (NO in step S4), the control unit 7 repeats steps S2 to S4. At this time, the gear mechanism of the actuator A1 is idled by the ratchet mechanism, the downward operation of the actuator A1 is prohibited, and the bottom 4 is maintained at the lower limit position.

Specifically, as shown in FIG. 4, when the height of the bottom 4 reaches the lower limit position of the movable range, the receiving member 66 of the links 61 and 62 interferes with the links 62 and 61, and the bottom 4 and the elevating frame A load such as 3 is received by the receiving member 66. Then, the load applied to the telescopic rod R of the actuator A1 is reduced. When the load applied to the telescopic rod R is less than the reference load, the gear mechanism of the actuator A1 is idled by the ratchet mechanism, the downward operation of the actuator A1 is prohibited, and the bottom 4 is maintained at the lower limit position.

If the downward movement is prohibited (YES in step S3), if step S5 is executed without executing step S4, when the height of the bottom 4 reaches the lower limit position of the movable range, the actuator A1 Since the elevating frame 3 is raised by the upward operation (step S5), the bottom 4 cannot be maintained at the lower limit position.

However, the electric bed 1 does not raise the elevating frame 3 when the bottom 4 is not above the lower limit position (NO in step S4) even when the downward operation is prohibited (YES in step S3). , The bottom 4 can be maintained at the lower limit position.

A play is provided in the interlocking mechanism between the telescopic rod R of the actuator A1 and the elevating frame 3 via the bracket 65 and the X-shaped link mechanism 6. Therefore, the bottom 4 reaches the lower limit position before the telescopic rod R is fully contracted.

Although the flowchart of FIG. 7 has been described by taking as an example a downward operation in which the height lowering button 80D is pressed and the height of the bottom 4 is lowered by the actuator A1, the head lowering button 81D, the back lowering button 82D, and the foot lowering button are described. Even in the case of the downward movement in which the head bottom 41, the back bottom 42, the knee bottom 44, and the leg bottom 45 change their postures by the actuators A2, A3, and A4 when the 83D is pushed, the operation of the flowchart shown in FIG. 7 is executed. By doing so, the same effect can be obtained.

It should be noted that the electric bed 1 does not necessarily have to execute steps S3 to S5, and the bottom 4 may not be operated upward when the downward operation of the actuator A is prohibited.

1 Electric bed 2 Base unit 3 Elevating frame (reception member)
4 Bottom 6 X-type link mechanism 7 Control unit 8 Hand switch (operation unit)
21,21 Support frame 22 Leg seat 23,24,25 Support pillar 27 Connecting rod 31,31 Guide member 41 Head bottom 42 Back bottom 43 Seat bottom 44 Knee bottom 45 Leg bottom 51 Headboard 52 Footboard 61, 62 Link 63 Axis 64 Connecting rod 65 Bracket 66 Receiving member 80D Height down button 80U Height up button 81D Head down button 81U Head up button 82D Back down button 82U Back up button 83D Foot down button 83U Foot up button 86 Power switch 87 Display unit 211 Guide member 411,421,441,451 Movable frame 412 Hinge (reception member)
442 Hinge 422,443 Link mechanism A, A1, A2, A3, A4 Actuator AC, A1C, A2C, A3C, A4C Control module C Control box M Drive unit R Telescopic rod

Claims (3)

With the bottom
An actuator that changes the posture or height of the bottom,
A receiving member that receives the downward load of the bottom at the lower limit position in the movable range of the bottom.
An operation unit that receives user operation instructions and
A control unit that controls the operation of the actuator in response to an operation instruction received by the operation unit, and a control unit.
An electric bed including a prohibiting mechanism for prohibiting a downward operation of changing the posture or height of the bottom by the actuator when the load applied to the actuator is less than a predetermined reference load. The actuator is
With the motor
A telescopic rod connected to the bottom and a telescopic rod
It is equipped with a gear mechanism that expands and contracts the telescopic rod by the rotational driving force of the motor.
When the telescopic rod contracts, it moves downward.
When the telescopic rod is extended, the bottom is moved upward to change its posture or to be raised.
The electric bed according to claim 1, wherein the prohibition mechanism is a ratchet mechanism that prohibits the downward operation by idling the gear mechanism when the load in the direction of contracting the telescopic rod is less than the reference load. The control unit
When the downward operation of the actuator is prohibited and the bottom is located above the lower limit position during the descent period in which the operation instruction of the downward operation is received by the operation unit, the bottom is caused by the actuator. Performs an upward motion to change or raise the posture upward,
The electric bed according to claim 1 or 2, wherein when the downward movement of the actuator is prohibited and the bottom is located at the lower limit position during the descending period, the actuator is not allowed to perform the upward movement.

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