CN113975025A

CN113975025A - Chemotherapy nursing bed and operation method

Info

Publication number: CN113975025A
Application number: CN202111497007.5A
Authority: CN
Inventors: 赵洪梅
Original assignee: TUMOR HOSPITAL OF HARBIN MEDICAL UNIVERSITY
Current assignee: TUMOR HOSPITAL OF HARBIN MEDICAL UNIVERSITY
Priority date: 2021-12-09
Filing date: 2021-12-09
Publication date: 2022-01-28
Anticipated expiration: 2041-12-09
Also published as: CN113975025B

Abstract

A chemotherapy nursing bed and an operation method thereof comprise a bed body, wherein the side surface of the bed body is provided with a gap, the right side of the gap is provided with a recess, the lower part of a wheelchair seat is provided with four universal wheels, the front part of the wheelchair seat is provided with a pedal, the upper part of the wheelchair seat is provided with an upper plate, the middle of the upper plate is provided with a central hole, the upper plate is just clamped into the gap, the seat is fixedly connected with the upper part of the wheelchair seat, and a power device is rotationally connected with the seat; the backrest comprises a backrest body, a backrest hinge hole, a seat plate center shaft, a spline shaft and a connecting rod upper hole, wherein the two backrest rotating shafts are symmetrically arranged on the lower portions of two sides of the backrest body, the backrest hinge hole penetrates through the lower portion of the backrest rotating shaft, an adjusting groove is formed in the upper portion of the left backrest rotating shaft, threaded holes are formed in the lower portion of the adjusting groove, the two seat plate rotating shafts are symmetrically arranged on the left side and the right side of the seat plate, the seat plate hinge hole penetrates through the rear side of the seat plate, the seat plate center shaft is arranged in the middle of the lower portion of the seat plate, the spline shaft is arranged on the lower portion of the seat plate center shaft, and the connecting rod upper hole is formed in the upper portion of the connecting rod.

Description

Chemotherapy nursing bed and operation method

Technical Field

The invention relates to the field of nursing beds, in particular to a chemotherapy nursing bed and an operation method.

Background

The patient receives the restriction of the state of an illness after the chemotherapy, and some patients can't transfer voluntarily, need to move the patient on the wheelchair, and the patient is very hard in the conversion between bed body and wheelchair, but also can cause patient's injury, needs a kind of rehabilitation bed of automatic conversion between bed body and wheelchair.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a chemotherapy nursing bed which can be freely switched between a bed body and a wheelchair without moving a patient and an operation method thereof.

The purpose of the invention is realized by the following technical scheme:

the utility model provides a chemotherapy nursing bed, includes the bed body, wheelchair seat, power device, and the seat includes back, seat, connecting rod, handrail, and power device includes base, drive seat, moving axis, the bed side has the breach, and the breach right side has sunkenly, and wheelchair seat lower part has four universal wheels, and wheelchair seat front portion has the footboard, and wheelchair seat upper portion has the upper plate, has the centre bore in the middle of the upper plate, and inside the breach was gone into to the right good card of upper plate, seat fixed connection wheelchair seat support upper portion, power device rotated and connects the seat.

The backrest comprises a backrest body, a seat plate and a seat plate, wherein the backrest body is provided with two backrest rotating shafts which are symmetrically arranged, the backrest lower part is provided with a through backrest hinge hole, the left backrest rotating shaft upper part is provided with an adjusting groove, the adjusting groove lower part is provided with a threaded hole, the left and right sides of the seat plate are provided with two seat plate rotating shafts which are symmetrically arranged, the rear side of the seat plate is provided with a through seat plate hinge hole, the middle of the lower part of the seat plate is provided with a seat plate center shaft, the lower part of the seat plate center shaft is provided with a spline shaft, the upper part of a connecting rod is provided with an upper hole of the connecting rod, the lower part of the connecting rod is provided with a lower hole of the connecting rod, the rear part of the armrest is provided with a rear hole of the armrest, the front hole of the armrest is provided with a front hole of the armrest, the seat plate hinge hole is hinged with the backrest hinge hole, the seat plate rotating shaft is hinged with a lower hole of the connecting rod, the armrest rear hole is hinged with the armrest on the same side, and the bolt is rotatably connected with the threaded hole.

The middle of the base is provided with a base hole, one side of the base hole is provided with two bearing seats, the rear side of the base is provided with a rear plate, the middle of the rear plate is provided with a rear plate groove, the middle of the driving seat is provided with an inner hole, the cylindrical surface of the driving seat is provided with a driving groove, the upper part of the driving groove is provided with an upper horizontal groove, the middle of the driving groove is provided with a spiral groove, the lower part of the driving seat is provided with a lower horizontal groove, the middle of the lower part of the driving seat is provided with a central shaft, the upper part of the driving seat is provided with a flange, the upper part of the flange is provided with two symmetrically arranged supporting plates, the upper part of the two supporting plates is provided with an upper plate, the middle of the upper plate is provided with a spline hole, the outer side of the lower part of the cylindrical surface of the moving shaft is provided with a cam rod, the central shaft penetrates through a turbine and the base hole from the upper part, the central shaft is rotatably connected with the base hole, the driving seat rotates in the base hole, the turbine is fixedly connected with the central shaft, the two sides of the worm respectively rotatably, the bearing seats, the worm rotates in the bearing seats, the worm and the worm is meshed with the turbine, the movable shaft is connected with the inner hole in a sliding mode, the movable shaft slides in the inner hole, the cam rod is connected with the driving groove in a sliding mode, the front portion of the cam rod is clamped in the groove of the rear plate, the seat plate central shaft penetrates through the central hole and the spline hole from the upper portion, the upper portion of the seat plate central shaft is connected with the central hole in a sliding mode, the seat plate slides in the central hole, the spline shaft is connected with the spline hole in a conditional mode, and the lower portion of the spline shaft is placed on the upper portion of the movable shaft.

Has the advantages that:

the invention can freely change between the bed body and the wheelchair, does not need to move the patient, is time-saving and labor-saving, has high safety, the driving groove is divided into a spiral groove, an upper horizontal groove and a lower horizontal groove, one part of the driving seat realizes three functions of lifting, turning and positioning, when the cam rod is contacted with the spiral groove, the spiral groove drives the invention to lift, and simultaneously the spline shaft is combined with the spline hole, when the cam rod is contacted with the upper horizontal groove, the invention can rotate, the upper horizontal groove is just 90 degrees, when the cam rod moves to the tail end of the upper horizontal groove, the chair just turns 90 degrees, and the function of limiting and positioning is realized, when the invention lifts and turns, the patient is on the bed, the safety of the patient is effectively protected, the bolt props against the side surface of the handrail, the chair stably keeps the wheelchair state, can not loosen, the use safety is ensured, the power mechanism adopts a worm turbine, the transmission ratio is high, when the invention is rotated and lifted, the worm and the turbine are stable, the self-locking function of the worm and the turbine enables the worm and the turbine to be kept in a stable state at any time, the parts are smoothly matched with each other, jamming is prevented, stress is balanced, balance is good, and safety coefficient is improved.

Drawings

Fig. 1 is a structural schematic diagram of the using state of the chemotherapy nursing bed.

Fig. 2 is a schematic structural view of the chemotherapy nursing bed in the using state.

Fig. 3 is a bottom structure schematic view of the chemotherapy nursing bed.

FIG. 4 is a schematic structural diagram of the bed body of the present invention.

FIG. 5 is a schematic view of the wheelchair seat according to the present invention.

Fig. 6 is a schematic view of the seat structure according to the invention.

Fig. 7 is a schematic diagram of the seat explosion structure according to the invention.

Fig. 8 is a schematic diagram of the front side structure of the power device.

Fig. 9 is a schematic structural diagram of the power device.

Fig. 10 is a schematic view of the base structure of the invention.

Fig. 11 is a schematic structural view of a driving seat according to the present invention.

Fig. 12 is a schematic sectional view of the driving seat according to the present invention.

Fig. 13 is a schematic view of the structure of the driving groove according to the invention.

Fig. 14 is a schematic view of a movable shaft structure according to the invention.

Detailed Description

The invention is explained in more detail below with reference to the figures and examples:

a chemotherapy nursing bed comprises a bed body 110, a wheelchair seat 120, a seat 200 and a power device 300, wherein the seat 200 comprises a backrest 210, a seat plate 220, a connecting rod 230 and an armrest 240, the power device 300 comprises a base 310, a driving seat 320 and a moving shaft 330, a notch 111 is formed in the side face of the bed body 110, a recess 112 is formed in the right side of the notch 111, four universal wheels 124 are arranged on the lower portion of the wheelchair seat 120, a pedal 123 is arranged in the front portion of the wheelchair seat 120, an upper plate 121 is arranged on the upper portion of the wheelchair seat 120, a central hole 122 is formed in the middle of the upper plate 121, the upper plate 121 is just clamped into the notch 111, the seat 200 is fixedly connected with the upper portion of the wheelchair seat 120, and the power device 300 is rotatably connected with the seat 200.

The backrest 210 is provided with two symmetrically arranged backrest rotating shafts 213 at the lower parts of both sides, the backrest 210 is provided with a through backrest hinge hole 214 at the lower part, the left backrest rotating shaft 213 is provided with an adjusting groove 211 at the upper part, the adjusting groove 211 is provided with a threaded hole 212 at the lower part, the seat plate 220 is provided with two symmetrically arranged seat plate rotating shafts 221 at the left and right sides, the seat plate 220 is provided with a through seat plate hinge hole 222 at the rear side, the seat plate 220 is provided with a seat plate central shaft 223 at the middle part at the lower part, the seat plate central shaft 223 is provided with a spline shaft 224 at the lower part, the connecting rod 230 is provided with an upper connecting rod hole 231 at the upper part, the connecting rod 230 is provided with a lower connecting rod hole 232 at the lower part, the armrest 240 is provided with an armrest rear hole 241 at the rear part, the armrest 240 is provided with an armrest front hole 242 at the front part, the seat plate hinge hole 222 is hinged with the backrest hinge hole 214, the seat plate rotating shaft 221 at each side is hinged with a lower connecting rod hole 232, the backrest rotating shaft 213 at each side is hinged with an armrest rear hole 241, the armrest front hole 242 and the connecting rod upper connecting rod hole 231 at the same side, and the bolt 250 is rotatably connected with the threaded hole 212.

The base 310 has a base hole 312 in the middle, two bearing seats 311 are provided at one side of the base hole 312, a back plate 313 is provided at the back side of the base 310, a back plate groove 314 is provided in the middle of the back plate 313, an inner hole 321 is provided in the middle of the driving seat 320, a driving groove 322 is provided on the cylindrical surface of the driving seat 320, an upper horizontal groove 3222 is provided on the upper portion of the driving groove 322, a spiral groove 3221 is provided in the middle of the driving groove 322, a lower horizontal groove 3223 is provided on the lower portion of the driving seat 320, a central shaft 323 is provided in the middle of the lower portion of the driving seat 320, a flange 324 is provided on the upper portion of the driving seat 320, two support plates 325 are symmetrically arranged on the upper portion of the flange 324, an upper plate 326 is provided on the upper portion of the two support plates 325, a spline hole 327 is provided in the middle of the upper plate 326, a cam lever 331 is provided on the outer side of the cylindrical surface of the moving shaft 330, the central shaft 323 passes through the turbine 350 and the base hole 312 from the upper portion, the central shaft 323 is rotatably connected with the base hole 312, the turbine 350 fixedly connected with the central shaft 323, the two sides of the worm 340 are respectively and rotatably connected with the bearing seats 311 on the two sides, the worm 340 rotates in the bearing seats 311, the worm 340 and the worm wheel 350 are meshed with each other, the moving shaft 330 is slidably connected with the inner hole 321, the moving shaft 330 slides in the inner hole 321, the cam rod 331 is slidably connected with the driving groove 322, the front part of the cam rod 331 is clamped in the rear plate groove 314, the seat plate central shaft 223 penetrates through the central hole 122 and the spline hole 327 from the upper part, the upper part of the seat plate central shaft 223 is slidably connected with the central hole 122, the seat plate 220 slides in the central hole 122, the spline shaft 224 is conditionally connected with the spline hole 327, and the lower part of the spline shaft 224 is placed on the upper part of the moving shaft 330.

When the invention is used, the upper plate 121 and the seat plate 220 are clamped in the notch 111, the upper part of the seat plate 220 is flush with the bed body 110, the backrest 210 is placed on the upper part of the recess 112, the invention becomes a common bed body for patients to use, when the patient needs to be transferred, the patient is firstly held up together with the backrest 210, the patient forms a sitting posture with the backrest 210, when the backrest 210 is held up, the backrest 210 drives the handrails 240 to lift up, the handrails 240 form handrails on two sides, the handrails 240 drive the connecting rods 230 to stand up, at the moment, the bolts 250 are rotated to press the upper parts of the rear sides of the handrails 240, so that the handrails 240 can not rotate any more, the backrest 210, the seat plate 220, the connecting rods 230 and the handrails 240 form stable connection to form a wheelchair, the worm 340 is rotated, the worm 340 rotates to drive the turbine 350 to rotate, the turbine 350 rotates to drive the seat 320 to rotate, the seat 320 rotates, the cam rod 331 begins to be positioned in the lower horizontal groove 3223, and the moving shaft 330 is positioned at the lowest part, the driving seat 320 rotates, the cam rod 331 moves from the lower horizontal groove 3223 to the spiral groove 3221, the spiral groove 3221 drives the moving shaft 330 to move upwards along the back plate groove 314, the spline shaft 224 is driven by the moving shaft 330 to move upwards, the seat 200 integrally moves upwards, when the cam rod 331 moves from the spiral groove 3221 to the upper horizontal groove 3222, the moving shaft 330 stops moving upwards, the seat plate 220 is separated from the recess 112, the upper part of the spline shaft 224 is inserted into the spline hole 327, when the driving seat 320 rotates, the moving shaft 330 does not move upwards any more, the driving seat 320 drives the seat 200 to rotate through the spline shaft 224, the patient rotates together with the seat 200 with the face facing inwards, when the cam rod 331 rotates to the tail end of the driving groove 322, the seat 200 just rotates 90 degrees, the wheelchair seat 120, the seat 200 and the power device 300 form a finished wheelchair, the invention is slowly pulled backwards, and after the invention is separated from the notch 111, the two legs of the patient are placed on the upper part of the pedal 123, the invention can be pushed to move freely, when the movement is finished and the reset is needed, the invention is pushed to the front part of the notch 111, firstly, the two legs of the patient are lifted to be placed on the upper part of the bed body 110, the invention is pushed forwards until the upper plate 121 is clamped into the notch 111, the cam rod 331 is positioned in the upper horizontal groove 3222, the moving shaft 330 is positioned at a high position, the upper part of the spline shaft 224 is inserted into the spline hole 327, the worm 340 is rotated reversely, the seat 200 is driven to rotate reversely by the driving seat 320, when the seat 200 rotates for 90 degrees, the backrest 210 is just positioned at the upper part of the recess 112, the cam rod 331 moves to the spiral groove 3221 from the upper horizontal groove 3222, the spline shaft 224 is separated from the spline hole 327, the worm 340 continues to rotate, the cam 200 is not rotated, the moving shaft 330 begins to descend, when the belt rod 331 moves to the lower horizontal groove 3223 from the spiral groove 3221, the moving shaft 330 descends to the lowest position, the worm 340 stops rotating, the bolt 250 is loosened, and the backrest 210 and the patient are slowly laid backwards, the operation is completed by the backrest 210 being completely flat.

The invention can freely change between a bed body and a wheelchair without moving a patient, is time-saving and labor-saving, has high safety, the driving groove 322 is divided into the spiral groove 3221, the upper horizontal groove 3222 and the lower horizontal groove 3223, one part of the driving seat 320 realizes three functions of lifting, turning and positioning, when the cam rod 331 is contacted with the spiral groove 3221, the spiral groove 3221 drives the invention to lift, and simultaneously the spline shaft 224 is combined with the spline hole 327, when the cam rod 331 is contacted with the upper horizontal groove 3222, the invention can rotate, the upper horizontal groove 3222 is just 90 degrees, when the cam rod 331 moves to the tail end of the upper horizontal groove 3222, the chair 200 just rotates 90 degrees, and the function of limiting and positioning is realized, when the invention is lifted and turned, the patient is in bed, the safety of the patient is effectively protected, the bolt 250 supports against the side surface of the handrail 240, so that the chair 200 stably keeps the wheelchair state, can not loosen and ensures the use safety, the power mechanism adopts the worm and the worm wheel, the transmission ratio is high, the rotation and the lifting are stable, the self-locking function of the worm and the worm wheel ensures that the invention keeps a stable state at any time, the interaction and the matching among the parts are smooth, the blocking is prevented, the stress is balanced, the balance is good, and the safety coefficient is improved.

An operation method of a chemotherapy nursing bed comprises the following steps:

firstly, when a patient is transferred, the patient and the backrest 210 are held together, the patient forms a sitting posture with the backrest 210, the bolt 250 is rotated, the bolt 250 presses the upper part of the rear side of the armrest 240, the armrest 240 cannot rotate any more, the backrest 210, the sitting plate 220, the connecting rod 230 and the armrest 240 form stable connection, the worm 340 is rotated, the patient is driven to rotate 90 degrees by the invention, the invention is slowly pulled backwards, and after the patient is separated from the notch 111, the two legs of the patient are placed on the upper part of the pedal 123, so that the invention can be pushed to move freely.

Secondly, when the chair needs to be reset, the chair is pushed to the front part of the notch 111, firstly, the legs of the patient are lifted to be placed on the upper part of the bed body 110, the chair is pushed forwards until the upper plate 121 is clamped into the notch 111, the worm 340 is rotated reversely, when the chair 200 rotates for 90 degrees, the backrest 210 is just positioned on the upper part of the recess 112 and falls down, the bolt 250 is loosened, the backrest 210 and the patient are slowly laid down to the rear side, and the operation is completed when the backrest 210 is completely laid flat.

When the invention is used, the upper plate and the seat plate are clamped in the gap, the upper part of the seat plate is parallel and level with the bed body, the backrest is placed at the upper part of the recess, the invention becomes a common bed body for patients to use, when the patient needs to be transferred, the patient and the backrest are firstly held up together, the patient forms a sitting posture with the backrest, when the backrest is held up, the backrest drives the armrests to be lifted up, the armrests form armrests at two sides, the armrests drive the connecting rods to be erected, at the moment, the bolt is rotated to press the upper parts at the rear sides of the armrests, so that the armrests can not rotate any more, the backrest, the seat plate, the connecting rods and the armrests form stable connection to form a wheelchair, the worm is rotated to drive the turbine to rotate, the driving seat is rotated, the cam rod starts to be positioned in the lower horizontal groove, the moving shaft is positioned at the lowest part, the driving seat rotates, the cam rod moves from the lower horizontal groove to the spiral groove, the spiral groove can drive the moving shaft to move upwards along the rear plate groove, the spline shaft is driven by the moving shaft to move upwards, the seat integrally moves upwards, when the cam rod moves from the spiral groove to the upper horizontal groove, the moving shaft stops moving upwards, the seat plate is separated from the recess, the upper part of the spline shaft is inserted into the spline hole, when the driving seat rotates, the moving shaft does not move upwards any more, the driving seat drives the seat to rotate through the spline shaft, the patient rotates along with the seat, the face faces inwards, when the cam rod rotates to the tail end of the driving groove, the seat just rotates 90 degrees, the wheelchair seat, the seat and the power device form a finished wheelchair, the invention is slowly pulled backwards, after the invention is separated from the gap, the two legs of the patient are placed on the upper part of the pedal, the invention can be pushed to move freely, when the invention is moved to the front part of the gap, the two legs of the patient are firstly lifted to be placed on the upper part of the bed body, the invention is pushed forwards until the upper plate is completely clamped into the gap, the cam rod is arranged in the upper horizontal groove, the moving shaft is arranged at a high position, the upper part of the spline shaft is inserted into the spline hole, the worm is reversely rotated, the driving seat drives the seat to rotate reversely, when the seat rotates for 90 degrees, the backrest is just positioned at the upper part of the recess, the cam rod moves to the spiral groove from the upper horizontal groove, the spline shaft is separated from the spline hole, the worm continues to rotate, the seat does not rotate, the moving shaft begins to descend, when the cam rod is arranged to move to the lower horizontal groove from the spiral groove, the moving shaft descends to the lowest position, the worm stops rotating, the bolt is loosened, the backrest and the patient slowly fall backwards, the backrest is completely leveled, and the operation is completed.

Claims

1. A chemotherapy nursing bed is characterized by comprising a bed body, a wheelchair seat, a seat and a power device, wherein the seat comprises a backrest, a seat plate, a connecting rod and a handrail, the power device comprises a base, a driving seat and a moving shaft, a notch is formed in the side surface of the bed body, a recess is formed in the right side of the notch, four universal wheels are arranged at the lower part of the wheelchair seat, a pedal is arranged at the front part of the wheelchair seat, an upper plate is arranged at the upper part of the wheelchair seat, a center hole is formed in the middle of the upper plate, the upper plate is clamped into the notch, the seat is fixedly connected with the upper part of the wheelchair seat, and the power device is rotatably connected with the seat; the backrest comprises a backrest body, a seat plate and a seat plate, wherein the backrest body is provided with two backrest rotating shafts which are symmetrically arranged, the backrest lower part is provided with a through backrest hinge hole, the left backrest rotating shaft upper part is provided with an adjusting groove, the adjusting groove lower part is provided with a threaded hole, the left and right sides of the seat plate are provided with two seat plate rotating shafts which are symmetrically arranged, the rear side of the seat plate is provided with a through seat plate hinge hole, the middle of the lower part of the seat plate is provided with a seat plate center shaft, the lower part of the seat plate center shaft is provided with a spline shaft, the upper part of a connecting rod is provided with an upper hole of the connecting rod, the lower part of the connecting rod is provided with a lower hole of the connecting rod, the rear part of the armrest is provided with a rear hole of the armrest, the front hole of the armrest is provided with a front hole of the armrest, the seat plate hinge hole is hinged with the backrest hinge hole, the seat plate rotating shaft is hinged with a lower hole of the connecting rod, the armrest rear hole is hinged with the armrest on the same side, and the bolt is rotatably connected with the threaded hole.

2. The chemotherapy nursing bed of claim 1, wherein the base has a base hole in the middle, one side of the base hole has two bearing seats, the rear side of the base has a back plate, the middle of the back plate has a back plate groove, the middle of the driving seat has an inner hole, the cylindrical surface of the driving seat has a driving groove, the upper part of the driving groove has an upper horizontal groove, the middle of the driving groove has a spiral groove, the lower part of the driving seat has a lower horizontal groove, the middle of the lower part of the driving seat has a central shaft, the upper part of the driving seat has a flange, the upper part of the flange has two support plates symmetrically arranged, and the upper parts of the two support plates have an upper plate.

3. The chemotherapy nursing bed of claim 2, wherein the upper plate has a spline hole in the middle, the cam rod is provided on the outer side of the lower part of the cylindrical surface of the moving shaft, the central shaft passes through the turbine and the base hole from the upper part, the central shaft is rotatably connected with the base hole, and the driving seat rotates in the base hole.

4. The chemotherapy nursing bed of claim 3, wherein the worm wheel is fixedly connected to the central shaft, two sides of the worm are respectively and rotatably connected to the bearing seats at two sides, the worm rotates in the bearing seats, the worm and the worm wheel are meshed with each other, the moving shaft is slidably connected to the inner hole, and the moving shaft slides in the inner hole.

5. The chemotherapy nursing bed of claim 4, wherein the cam rod is slidably connected to the driving groove, the front part of the cam rod is clamped in the groove of the back plate, the seat plate central shaft passes through the central hole and the spline hole from the upper part, the upper part of the seat plate central shaft is slidably connected to the central hole, the seat plate slides in the central hole, the spline shaft is conditionally connected to the spline hole, and the lower part of the spline shaft is placed on the upper part of the movable shaft.

6. The method of claim 1, further comprising the steps of: firstly, when a patient is transferred, the patient and a backrest are held together, the patient forms a sitting posture along with the backrest, a bolt is rotated to press the upper part of the rear side of a handrail, so that the handrail can not rotate any more, the backrest, a sitting plate, a connecting rod and the handrail form stable connection, a worm is rotated, the invention drives the patient to rotate 90 degrees, the invention is slowly pulled backwards, and after the invention is separated from a gap, the two legs of the patient are placed on the upper part of a pedal, so that the invention can be pushed to freely move; and secondly, when the chair needs to be reset, the chair is pushed to the front part of the notch, the two legs of the patient are lifted to be placed on the upper part of the bed body, the chair is pushed forwards until the upper plate is clamped into the notch, the worm is rotated reversely, the backrest is just positioned on the upper part of the recess and falls down when the chair rotates by 90 degrees, the bolt is loosened, the backrest and the patient are slowly laid down to the rear side, and the operation is completed when the backrest is completely laid flat.