Medical treatment chair apparatus

Abstract

To provide a chair device for medical treatment capable of reducing an operation sound, suppressing the enlargement and cost increase of the device and suitably supporting the head of a patient.SOLUTION: This chair device 1A for medical treatment is provided with a back plate part, a bolster part movably attached to the back plate part, a cylinder rod mechanism 25 interposed between the back plate part and the bolster part, and a converter 33 for converting gas pressure from a pressure source 31 into liquid pressure, and the cylinder rod mechanism 25 is extended by the liquid pressure supplied from the converter 33.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a dental chair apparatus on which a patient sits during, for example, dental treatment. [Background technology]

[0002] In dental treatment, dental chairs are used for patients to sit on. These dental chairs are equipped with a headrest on which the patient's head rests. These dental chairs have a function to change the position of the headrest relative to the chair body depending on the posture of the chair body, the height of the patient, etc. (See, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-72335 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional medical chairs, the function of changing the position of the headrest is realized by providing an electric actuator or a hydraulic pump and a function for transmitting the driving force generated by these. Such electric actuators or hydraulic pumps are also commonly used to change the position (including posture) of the seat, backrest, etc. of the medical chair.

[0005] In such a medical chair, when the headrest position is changed using an electric actuator, the operating noise is loud and may cause discomfort to the patient. Furthermore, when the headrest position is changed using a hydraulic pump (liquid pressure), adjusting the large hydraulic pressure to a level suitable for changing the headrest position results in an increased device size, and using a solenoid valve or the like that can be operated by large hydraulic pressure results in an increased device cost. Furthermore, when the headrest position is changed using gas pressure such as an air cylinder, the air cylinder or the like may compress when a load is applied to the headrest, potentially resulting in an insufficient force to support the patient's head.

[0006] The present invention has been made in consideration of the above points, and its object is to provide a medical chair device that reduces operating noise, prevents the device from becoming larger and more expensive, and is capable of properly supporting the patient's head. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the medical chair device of the present invention comprises a chair body, a headrest movably attached to the chair body, a cylinder-rod mechanism interposed between the chair body and the headrest, and a converter that converts gas pressure from a pressure source into liquid pressure, and the cylinder-rod mechanism is extended by the liquid pressure supplied from the converter. [Effects of the Invention]

[0008] According to the present invention, gas pressure is converted into liquid pressure by a converter, and the headrest is moved by operating a piston-rod mechanism using this liquid pressure, thereby reducing operating noise, preventing the device from becoming larger and more expensive, and providing optimal support for the patient's head. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view schematically showing a medical chair apparatus according to a first embodiment of the present invention; [Figure 2]FIG. 2 is a rear view schematically showing the medical chair apparatus according to the first embodiment of the present invention, showing a state in which a cover and a holder cover have been removed. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 2 is a block diagram simply showing the circuits of a linear motion mechanism and a tilting mechanism in the medical chair device according to the first embodiment of the present invention. [Figure 6] FIG. 2 is a circuit diagram schematically illustrating a gas flow path and a liquid flow path of the medical chair apparatus according to the first embodiment of the present invention, and is a diagram for explaining a stopped state of the pillow section. [Figure 7] 1 is a circuit diagram schematically illustrating a gas flow path and a liquid flow path of a medical chair apparatus according to a first embodiment of the present invention, and is a diagram for explaining the lifting and forward tilting movements of a pillow section. FIG. [Figure 8] 1 is a circuit diagram schematically illustrating a gas flow path and a liquid flow path of a medical chair apparatus according to a first embodiment of the present invention, and is a diagram for explaining the lowering and backward tilting movements of a pillow section. FIG. [Figure 9] FIG. 10 is a block diagram simply showing the circuits of a linear motion mechanism and a tilting mechanism in a medical chair device according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a circuit diagram schematically showing gas flow paths and liquid flow paths of a medical chair apparatus according to a second embodiment of the present invention, illustrating a stopped state of the pillow section. [Figure 11] FIG. 10 is a circuit diagram schematically showing the gas flow path and the liquid flow path of the medical chair apparatus according to the second embodiment of the present invention, and is a diagram for explaining the lifting operation and the forward tilting operation of the pillow section. [Figure 12] FIG. 10 is a circuit diagram schematically showing the gas flow path and the liquid flow path of the medical chair apparatus according to the second embodiment of the present invention, and is a diagram for explaining the lowering operation and the backward tilting operation of the pillow section. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same elements will be given the same reference numerals, and duplicated explanations will be omitted. Note that expressions indicating directions such as front-back, up-down, left-right, etc. are based on the patient sitting on the treatment chair apparatus.

[0011] First Embodiment As shown in Fig. 1, a dental chair apparatus 1A according to a first embodiment of the present invention is a chair on which a patient sits during dental treatment, and includes a base 11, a seat 12, a leg rest 13, a back plate 14, and a pillow 15. The dental chair apparatus 1A also includes a leg rest holder 16, a back plate holder 17, a pillow holder 18, and a holder cover 19. The base 11, the seat 12, the back plate 14, and the back plate holder 17 form the chair body of the dental chair apparatus 1A.

[0012] <Base (leg)> The base 11 is a portion placed on the floor and houses a drive device (such as a hydraulic pump) for changing the positions (including posture) of the seat 12, the leg rest 13, and the back panel 14.

[0013] <Seat> The seat portion 12 is disposed on the base portion 11 and is a portion on which a patient sits.

[0014] <Leg rest and leg rest support (leg rest stay)> The leg rest 13 extends downward from the front and upper end of the base 11 and is a portion on which the patient's legs (including feet) are placed. The leg rest 13 is connected to the base 11 via a leg rest holder 16 so that its position can be changed. The leg rest holder 16 is a metal member.

[0015] <Backboard section (backrest) and backboard support section (backrest stay)> The back plate 14 extends upward from the rear end and upper end of the base 11 and is the portion on which the patient's back rests. The back plate 14 is connected to the base 11 via a back plate holder 17 so that its position can be changed. The back plate holder 17 is a resin member that curves forward as it extends upward.

[0016] <Pillow part (headrest), pillow part support part (headrest stay), and support part cover> The pillow section 15 extends upward from the upper end of the back plate section 14 and is the section on which the patient's head rests. The pillow section 15 is connected to the back plate section 14 via a pillow section holder 18 so that its position can be changed (linearly and tiltably moved). The pillow section holder 18 is a resin member that curves forward as it extends upward. The holder cover 19 is a resin cylindrical member that covers the pillow section holder 18.

[0017] <Linear motion mechanism and tilting mechanism> The medical chair apparatus 1A includes a frame 21, a cover 22, a pair of left and right slide rails 23, 23, a slide panel 24, a linear motion cylinder-rod mechanism 25X (25), and a tilting cylinder-rod mechanism 25Y (25). The medical chair apparatus 1A also includes a guide holder 26, a guide 27, and a bracket 28. The frame 21, slide rail 23, tilting cylinder-rod mechanism 25Y, guide holder 26, bracket 28, and pillow holder 18 form a linear motion mechanism XA that supports the pillow 15 so that it can move linearly. The guide holder 26, guide 27, bracket 28, and pillow holder 18 form a tilting mechanism YA that supports the pillow 15 so that it can tilt.

[0018] <frame> The frame 21 is a metal plate-like member that is provided at the rear of the back plate portion 14 and forms the framework of the back plate portion 14 .

[0019] <Cover> The cover 22 is attached to the rear surface of the frame 21 and is a lid-like member made of resin or metal that cooperates with the frame 21 to form an accommodation space in which the linear motion mechanism X1 and the tilting mechanism Y1 are accommodated.

[0020] <Slide rail> The pair of left and right slide rails 23, 23 are metal members attached to the rear surface of the frame 21 in a position extending in the vertical direction.

[0021] <Slide panel> The slide panel 24 is a metal plate-like member that is installed on the slide rails 23, 23. The slide panel 24 is supported by the slide rails 23, 23 so as to be slidable in the up and down direction.

[0022] <Linear cylinder rod mechanism> The linear motion cylinder-rod mechanism 25X is disposed on the rear side of the frame 21, and linearly moves (raises and lowers) the pillow section 15 via the linear motion mechanism XA. A cylinder 25a (see FIG. 5) of the linear motion cylinder-rod mechanism 25X is attached to the frame 21. A rod 25c (see FIG. 5) of the linear motion cylinder-rod mechanism 25X is attached to the slide panel 24 (or the guide holding section 26). The configuration of the linear motion cylinder-rod mechanism 25X will be described in detail later.

[0023] <Tilt cylinder rod mechanism> The tilting cylinder-rod mechanism 25Y is disposed on the front side of the slide panel 24 and tilts (tilts forward and backward) the pillow section 15 via the tilting mechanism YA. The cylinder 25a of the tilting cylinder-rod mechanism 25Y is attached to the slide panel 24 so as to be rotatable relative to it about a rotation axis Ax1 extending left and right. The rod 25c of the tilting cylinder-rod is attached to the bracket 28 so as to be rotatable relative to it about a rotation axis Ax2 extending left and right. The configuration of the tilting cylinder-rod mechanism 25Y will be described in detail later.

[0024] <Guide holding part> The guide holding portion 26 is a long groove-shaped member made of metal or resin and attached to the front surface of the slide panel 24. The guide holding portion 26 extends in the vertical direction so that the upper portion of the guide holding portion 26 protrudes above the slide panel 24. The assembly of the guide holding portion 26 and the slide panel 24 is equipped with a tilting mechanism YA.

[0025] <Guide> The guide 27 is a bearing held at the upper end of the guide holding portion 26. The guide 27 guides the movement of the pillow portion holding portion 18 along the curvature direction of the pillow portion holding portion 18.

[0026] <bracket> The bracket 28 is a metal member that connects the tip end (upper end) of the rod 25c of the tilting cylinder rod mechanism 25Y and the base end (lower end) of the pillow portion holding portion 18.

[0027] <Gas (gas pressure) and liquid (liquid pressure) circuits> The medical chair apparatus 1A includes gas and liquid circuits in the linear motion mechanism XA and gas and liquid circuits in the tilting mechanism YA. The circuits in the linear motion mechanism XA and the circuits in the tilting mechanism YA have the same circuit configuration, and therefore will be described using the same drawings (Figs. 6 to 8).

[0028] <Linear motion circuit configuration> As shown in Figures 5 and 6, the medical chair device 1A includes a pressure source 31, a first switching valve 32A1 and a second switching valve 32A2 (direct acting first switching valve 32A1X, direct acting second switching valve 33A2X), a converter 33 (direct acting converter 33X), a cylinder-rod mechanism 25 (direct acting cylinder-rod mechanism 25X), and a tank 34 as gas and liquid circuits in the direct acting mechanism XA.

[0029] <Tilt circuit configuration> The medical chair device 1A includes a pressure source 31, a first switching valve 32A1 and a second switching valve 32A2 (a first switching valve for tilting 32A1Y and a second switching valve for tilting 32A2Y), a converter 33 (a converter for tilting 33Y), a cylinder-rod mechanism 25 (a cylinder-rod mechanism for tilting 25Y), and a tank 34 as gas and liquid circuits in the tilting mechanism YA.

[0030] In the examination chair apparatus 1A, the pressure source 31 and the tank 34 are shared by the circuits of the linear motion mechanism XA and the tilting mechanism YA. The pressure source 31 is, for example, a compressor that supplies compressed air to dental treatment instruments. The converter 33 is a device that converts the gas pressure from the pressure source 31 into liquid pressure. The converter 33 will be described in detail later.

[0031] <Gas flow path> As shown in FIG. 6 , the medical chair apparatus 1A includes gas flow paths in each of the circuits of the linear motion mechanism XA and the tilting mechanism YA, including a first gas flow path 41, a second gas flow path 42, a third gas flow path 43, and a pair of fourth gas flow paths 44A1 and 44A2. The first gas flow path 41 connects the pressure source 31 to the first switch valve 32A1 and the second switch valve 32A2 so that gas can flow therethrough. The second gas flow path 42 connects the first switch valve 32A1 to the converter 33 so that gas can flow therethrough. The third gas flow path 43 connects the second switch valve 32A2 to the cylinder-rod mechanism 25 so that gas can flow therethrough. The fourth gas flow path 44A1 connects the first switch valve 32A1 to the tank 34 so that gas can flow therethrough. The fourth gas flow path 44A2 connects the second switch valve 32A2 to the tank 34 so that gas can flow therethrough.

[0032] The first gas flow path 41 and the second gas flow path 42 constitute a first connection path that allows gas to flow between the pressure source 31 and the converter 33. The third gas flow path 43 constitutes a second connection path that allows gas to flow between the switching valve (second switching valve 32A2) and the cylinder-rod mechanism 25.

[0033] <Liquid flow path> The medical chair apparatus 1A includes a liquid flow path 51 as a liquid flow path in each of the circuit for linearly moving the pillow portion 15 and the circuit for tilting the pillow portion 15. The liquid flow path 51 connects the converter 33 and the cylinder-rod mechanism 25 so that liquid can flow therethrough.

[0034] <Valve on the circuit> The medical chair apparatus 1A includes a check valve 35, a flow valve 36, a flow valve 37, an on-off valve 38, and a flow valve 39.

[0035] <Pressure source> The pressure source 31 is a supply source (for example, a tank for storing gas) of gas (for example, compressed air) for gas pressure. The pressure source 31 can be shared with a pressure source (air compressor) for supplying gas (compressed air) to other devices (dental treatment instruments, for example, handpieces for cutting a patient's teeth) in a dental treatment unit equipped with the treatment chair device 1A. The air compressor as the pressure source 31 can be operated by, for example, operating a foot controller (not shown) by a medical professional (dentist, dental assistant, etc.).

[0036] <Check valve> The check valve 35 is provided in the first gas flow path 41 downstream of the pressure source 31 and upstream of the flow valve 36. The check valve 35 is a one-way valve that allows gas to flow from the pressure source 31 side to the first switch valve 32A1 and second switch valve 32A2 side in the first gas flow path 41, but prohibits gas from flowing from the first switch valve 32A1 and second switch valve 32A2 side to the pressure source 31 side.

[0037] <Flow valve> The flow rate valve 36 is provided downstream of the check valve 35 and upstream of the first switching valve 32A1 and the second switching valve 32A2 in the first gas flow path 41. The flow rate valve 36 is a valve that stabilizes the flow rate of the gas flowing through the first gas flow path 41.

[0038] <First switching valve> The first switching valve 32A1 is interposed between the first gas flow path 41, the second gas flow path 42, and the fourth gas flow path 44A1. The first switching valve 32A1 is a three-port solenoid valve that can switch between a gas supply state and a gas discharge state, which will be described below.

[0039] The gas supply state is a state in which the first gas flow path 41 and the second gas flow path 42 are connected to allow gas to flow, and the fourth gas flow path 44A1 is blocked from the first gas flow path 41 and the second gas flow path 42 to prevent gas from flowing. When the first switch valve 32A1 is in the gas supply state, gas from the pressure source 31 is supplied to the gas chamber 33a1 of the converter 33 via the first gas flow path 41, the first switch valve 32A1, and the second gas flow path 42.

[0040] The gas discharge state is a state in which the second gas flow path 42 and the fourth gas flow path 44A1 are connected to allow gas to flow, and the first gas flow path 41 is blocked from the second gas flow path 42 and the fourth gas flow path 44A1 so that gas cannot flow. When the first switch valve 32A1 is in the gas discharge state, gas from the gas chamber 33a1 of the converter 33 is discharged from the tank 34 to the atmosphere via the second gas flow path 42, the first switch valve 32A1, and the fourth gas flow path 44A1.

[0041] <Second switching valve> The second switching valve 32A2 is interposed between the first gas flow path 41, the third gas flow path 43, and the fourth gas flow path 44A2. The second switching valve 32A2 is a three-port solenoid valve that can be switched between the following two states.

[0042] The gas supply state is a state in which the first gas flow path 41 and the third gas flow path 43 are connected to allow gas to flow, and the fourth gas flow path 44A2 is blocked from the first gas flow path 41 and the third gas flow path 43 to prevent gas from flowing through them. When the second switching valve 32A2 is in the gas supply state, gas from the pressure source 31 is supplied to the gas chamber 25a2 of the cylinder-rod mechanism 25 via the first gas flow path 41, the second switching valve 32A2, and the third gas flow path 43.

[0043] The gas discharge state is a state in which the third gas flow path 43 and the fourth gas flow path 44A2 are connected to allow gas to flow, and the first gas flow path 41 is blocked from the third gas flow path 43 and the fourth gas flow path 44A2 so that gas cannot flow therethrough. When the second switching valve 32A2 is in the gas discharge state, gas from the gas chamber 25a2 of the cylinder-rod mechanism 25 is discharged from the tank 34 to the atmosphere via the third gas flow path 43, the second switching valve 32A2, and the fourth gas flow path 44A2.

[0044] <Converter> The converter 33 is interposed between the second gas flow path 42 and the liquid flow path 51. The converter 33 converts the gas pressure from the pressure source 31 into liquid pressure and supplies it to the cylinder-rod mechanism 25. The converter 33 includes a housing 33a and a partition 33b that separates the interior of the housing 33a into a gas chamber 33a1 and a liquid chamber 33a2.

[0045] The gas chamber 33a1 is a portion filled with gas, and is connected to the second gas flow path 42 so that the gas can flow therethrough.

[0046] The liquid chamber 33a2 is a portion filled with a liquid (for example, oil), and is connected to the liquid flow path 51 so that the liquid can flow therethrough.

[0047] The partition portion 33b is configured to be movable or deformable by the gas pressure in the gas chamber 33a1 and the liquid pressure in the liquid chamber 33a2, and converts gas pressure into liquid pressure and liquid pressure into gas pressure by such movement or deformation.

[0048] In this embodiment, the linear motion converter 33X and the tilt motion converter 33Y are fixed to the frame 21. The linear motion converter 33X and the tilt motion converter 33Y do not slide due to the linear motion mechanism XA, and the tilt motion converter 33Y does not slide due to the tilt motion mechanism YA. This allows the weight of the movable parts (sliding parts) of the linear motion mechanism XA and the movable parts (sliding parts) of the tilt motion mechanism YA to be reduced.

[0049] The converter 33 may be configured without the partition 33b. In this case, the second gas flow path 42 communicates with the interior of the converter 33 at the upper end (e.g., upper wall) of the converter 33, and the liquid flow path 51 communicates with the interior of the converter 33 at the lower end (e.g., lower wall) of the converter 33. In the converter 33 configured as above, the upper part of the converter 33 is filled with a gas having a relatively low specific gravity, and the lower part of the converter 33 is filled with a liquid having a relatively high specific gravity. The gas and liquid in the converter 33 are in contact with each other without mixing due to the difference in specific gravity, and can transmit pressure to each other.

[0050] <Flow valve> The flow rate valve 37 is provided in the third gas flow path 43. The flow rate valve 37 is a valve that keeps the flow rate of the gas flowing through the third gas flow path 43 constant.

[0051] <Shut-off valve> The on-off valve 38 is provided in the liquid flow path 51 downstream of the converter 33 and upstream of the flow valve 39. The on-off valve 38 is an electromagnetic valve that can be switched between an open state that allows the flow of liquid and a closed state that blocks the flow of liquid.

[0052] <Flow valve> The flow rate valve 39 is provided in the liquid flow path 51 downstream of the on-off valve 38 and upstream of the cylinder-rod mechanism 25. The flow rate valve 39 is a valve that keeps the flow rate of the liquid flowing through the liquid flow path 51 constant.

[0053] <Cylinder rod mechanism> The cylinder-rod mechanism 25 is interposed between the third gas flow path 43 and the liquid flow path 51. The cylinder-rod mechanism 25 retracts a rod 25c by liquid pressure from the converter 33 and by gas pressure from the pressure source 31. The cylinder-rod mechanism 25 includes a cylinder 25a, a piston 25b that divides the interior of the cylinder 25a into a liquid chamber 25a1 and a gas chamber 25a2, and a rod 25c.

[0054] The liquid chamber 25a1 is a portion that can be filled with liquid, and is connected to the liquid flow path 51 so that the liquid can flow therethrough.

[0055] The gas chamber 25a2 is a portion that can be filled with gas, and is connected to the third gas flow path 43 so that the gas can flow therethrough.

[0056] The piston 25b is configured to be movable by the liquid pressure in the liquid chamber 25a1 and the gas pressure in the gas chamber 25a2.

[0057] Rod 25c extends from and retracts into cylinder 25a in response to the movement of piston 25b. The base end of piston 25b is connected to the side of gas chamber 25a2 of piston 25b. The tip end of piston 25b protrudes outside cylinder 25a.

[0058] <Tank> The tank 34 is a housing made of resin or metal that receives the gas discharged from at least one of the piston-rod mechanism 25 and the converter 33 (both in this embodiment). The tank 34 is configured to separate and store liquid from the gas discharged into the tank 34 via the fourth gas flow paths 44A1 and 44A2, and to be able to discharge the separated liquid to the outside of the tank 34.

[0059] <Operation section, etc.> As shown in FIG. 2, the medical chair device 1A includes an operating unit 61, a linear position detecting unit 62, a tilting position detecting unit 63, and a control unit 64.

[0060] <Operation section> The operation unit 61 is disposed at the upper end of the cover 22. The operation unit 61 is operated by a medical professional (dentist, dental assistant, etc.) to move the pillow section 15 in a linear motion direction (up / down) or in a tilting direction (tilt forward / backward). The operation unit 61 outputs a control signal corresponding to the operation result of the operation unit 61 to the first switching valve 32A1, the second switching valve 32A2, and the on-off valve 38 of the linear motion mechanism XA and the tilting mechanism YA, or to the control unit 64. The operation unit 61 can be embodied, for example, by a button, a touch panel, a joystick, etc., and may be disposed at a position other than the upper end of the cover 22. For example, the examination chair apparatus 1A may be configured such that the joystick as the operation unit 61 is disposed at the bottom of the base 11, on the foot controller (not shown), or the like.

[0061] <Linear position detection unit> The linear motion position detection unit 62 detects parameters related to the position of the pillow part 15 moved in the linear motion direction by the linear motion mechanism XA and the linear motion cylinder-rod mechanism 25X, and outputs the detection result to the control unit 64. In this embodiment, the linear motion position detection unit 62 includes a spiral plate member inserted into a groove portion arranged in the slide panel 24, and a rotary encoder that detects the rotation angle of the spiral plate member.

[0062] <Tilt position detection unit> The tilt position detection unit 63 detects parameters related to the position of the pillow part 15 moved in the tilt direction by the tilt mechanism YA and the tilt cylinder / rod mechanism 25Y, and outputs the detection results to the control unit 64.

[0063] <Control unit> The control unit 64 is composed of a CPU (Central Processing Unit), ROM (Read-Only Memory), RAM (Random Access Memory), input / output circuits, etc. The control unit 64 can operate the direct-acting cylinder-rod mechanism 25X by controlling the direct-acting first selector valve 32A1X, the direct-acting second selector valve 32A2X, and the direct-acting on-off valve 38 based on the detection result of the direct-acting position detection unit 62. The control unit 64 can operate the tilting cylinder-rod mechanism 25Y by controlling the tilting first selector valve 32A1Y, the tilting second selector valve 32A2Y, and the tilting on-off valve 38 based on the detection result of the tilting position detection unit 63. For example, the control unit 64 can operate the direct-acting cylinder-rod mechanism 25X and the tilting cylinder-rod mechanism 25Y to realize a position of the pillow section 15 corresponding to the orientation of the back plate section 14 based on the detection result of the orientation detection unit that detects the orientation of the back plate section 14.

[0064] <Example of operation> Next, an example of the operation of the medical chair device 1A will be described in the order of linear movement and tilting of the pillow portion 15.

[0065] <Linear motion: Stop> First, the stopped state of the pillow part 15 will be described as the state before and after the pillow part 15 moves in the direct movement direction. As shown in Fig. 6, when the operating part 61 (see Fig. 2) is not operated, the direct movement on-off valve 38 is in a closed state. Furthermore, when the operating part 61 is not operated, the direct movement first switching valve 32A1X is in a gas supply state. Furthermore, when the operating part 61 is not operated, the direct movement second switching valve 32A2X is in a gas discharge state.

[0066] Here, the liquid pressure in the liquid chamber 33a2 of the direct drive converter 33X is maintained by closing the direct drive on-off valve 38. Also, the gas pressure in the gas chamber 33a1 of the direct drive converter 33X becomes equal to the liquid pressure in the liquid chamber 33a2.

[0067] Meanwhile, the liquid pressure in the liquid chamber 25a1 of the direct acting cylinder-rod mechanism 25X is maintained by closing the on-off valve 38. Also, the gas pressure in the gas chamber 25a2 of the direct acting cylinder-rod mechanism 25X becomes equal to the liquid pressure in the liquid chamber 25a1.

[0068] As a result, the direct-acting cylinder-rod mechanism 25X maintains the position in the direct-acting direction of the pillow part 15. Furthermore, the pillow part 15 appropriately supports the patient's head by the fluid pressure from the direct-acting converter 33X.

[0069] <Linear motion: rising (extension)> As shown in Fig. 7, when the operation unit 61 (see Fig. 2) is operated for ascent, the direct acting first switching valve 32A1X is in a gas supply state based on a control signal from the operation unit 61. Furthermore, when the operation unit 61 is operated for ascent, the direct acting second switching valve 32A2X is in a gas discharge state based on a control signal from the operation unit 61. Furthermore, when the operation unit 61 is operated for ascent, the direct acting on-off valve 38 is in an open state based on a control signal from the operation unit 61.

[0070] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 33a1 of the direct drive converter 33X via the first gas flow path 41, the direct drive first switching valve 32A1X, and the second gas flow path 42. Also, a portion of the liquid (liquid pressure) in the liquid chamber 33a2 of the direct drive converter 33X is supplied to the liquid chamber 25a1 of the direct drive cylinder-rod mechanism 25X via the liquid flow path 51 by the gas pressure of the gas chamber 33a1.

[0071] Meanwhile, a portion of the gas in the gas chamber 25a2 of the direct acting cylinder-rod mechanism 25X is discharged to the atmosphere from the tank 34 via the third gas flow path 43, the second direct acting switching valve 32A2X and the fourth gas flow path 44A2 due to the liquid pressure in the liquid chamber 25a1.

[0072] As a result, the rod 25c of the direct-acting cylinder-rod mechanism 25X moves in the extension direction. That is, the direct-acting cylinder-rod mechanism 25X raises the pillow part 15 via the direct-acting mechanism XA. The pillow part 15 also moves in a direction that lifts the patient's head while supporting it with the fluid pressure from the direct-acting converter 33X.

[0073] <Direct action: Downward (retraction)> As shown in Fig. 8, when the operation unit 61 (see Fig. 2) is operated for descent, the direct acting first switching valve 32A1X is in a gas discharge state based on a control signal from the operation unit 61. Furthermore, when the operation unit 61 is operated for descent, the direct acting second switching valve 32A2X is in a gas supply state based on a control signal from the operation unit 61. Furthermore, when the operation unit 61 is operated for descent, the direct acting on-off valve 38 is in an open state based on a control signal from the operation unit 61.

[0074] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 25a2 of the direct drive cylinder-rod mechanism 25X via the first gas flow path 41, the direct drive second switching valve 32A2X, and the third gas flow path 43. Also, part of the liquid in the liquid chamber 25a1 of the direct drive cylinder-rod mechanism 25X is returned to the liquid chamber 33a2 of the direct drive converter 33X via the liquid flow path 51 by the gas pressure of the gas chamber 25a2.

[0075] Meanwhile, a portion of the gas in the gas chamber 33a1 of the direct-acting converter 33X is discharged to the atmosphere from the tank 34 via the second gas flow path 42, the direct-acting first switching valve 33A1X and the fourth gas flow path 44A1 due to the liquid pressure in the liquid chamber 33a2.

[0076] As a result, the rod 25c of the direct-acting cylinder-rod mechanism 25X moves in the retracted direction. That is, the direct-acting cylinder-rod mechanism 25X lowers the pillow part 15 via the direct-acting mechanism XA. The pillow part 15 also moves in the direction of lowering the patient's head while supporting it with the fluid pressure from the direct-acting converter 33X.

[0077] <Tilt: Stop> First, the stopped state of the pillow part 15 will be described as the state before and after the operation of the pillow part 15 in the tilting direction. As shown in Fig. 6, when the operating part 61 (see Fig. 2) is not operated, the tilting opening / closing valve 38 is in a closed state. Also, when the operating part 61 is not operated, the tilting first switching valve 32A1Y is in a gas supply state. Also, when the operating part 61 is not operated, the tilting second switching valve 32A2Y is in a gas discharge state.

[0078] Here, the liquid pressure in the liquid chamber 33a2 of the tilting converter 33Y is maintained by closing the tilting on-off valve 38. Also, the gas pressure in the gas chamber 33a1 of the tilting converter 33Y becomes equal to the liquid pressure in the liquid chamber 33a2.

[0079] Meanwhile, the liquid pressure in the liquid chamber 25a1 of the tilting cylinder / rod mechanism 25Y is maintained by closing the on-off valve 38. Also, the gas pressure in the gas chamber 25a2 of the tilting cylinder / rod mechanism 25Y becomes equal to the liquid pressure in the liquid chamber 25a1.

[0080] As a result, the tilting cylinder-rod mechanism 25Y maintains the position of the pillow section 15 in the linear direction. Also, the pillow section 15 appropriately supports the patient's head by the fluid pressure from the tilting converter 33Y.

[0081] <Tilt: Forward tilt (extension)> As shown in Fig. 7, when the operating unit 61 (see Fig. 2) is operated to tilt forward, the tilting first switch valve 32A1Y is in a gas supply state based on a control signal from the operating unit 61. Furthermore, when the operating unit 61 is operated to tilt forward, the tilting second switch valve 32A2Y is in a gas discharge state based on a control signal from the operating unit 61. Furthermore, when the operating unit 61 is operated to tilt forward, the tilting on-off valve 38 is in an open state based on a control signal from the operating unit 61.

[0082] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 33a1 of the tilting converter 33Y via the first gas flow path 41, the tilting first selector valve 32A1Y, and the second gas flow path 42. Also, a portion of the liquid (liquid pressure) in the liquid chamber 33a2 of the tilting converter 33Y is supplied to the liquid chamber 25a1 of the tilting cylinder / rod mechanism 25Y via the liquid flow path 51 by the gas pressure of the gas chamber 33a1.

[0083] Meanwhile, a portion of the gas in the gas chamber 25a2 of the tilting cylinder / rod mechanism 25Y is discharged from the tank 34 to the atmosphere via the third gas flow path 43, the second tilting switching valve 32A2Y and the fourth gas flow path 44A1 due to the liquid pressure in the liquid chamber 25a1.

[0084] As a result, the rod 25c of the tilting cylinder-rod mechanism 25Y moves in the extension direction. That is, the tilting cylinder-rod mechanism 25Y tilts the pillow section 15 forward via the tilting mechanism YA. Also, the pillow section 15 moves in a direction that lifts the patient's head while supporting it with the fluid pressure from the tilting converter 33Y.

[0085] <Tilt: Retroversion (retraction)> As shown in Fig. 8, when the operating unit 61 (see Fig. 2) is operated to tilt backward, the tilting first switch valve 32A1Y is set to a gas discharge state based on a control signal from the operating unit 61. Furthermore, when the operating unit 61 is operated to tilt backward, the tilting second switch valve 32A2Y is set to a gas supply state based on a control signal from the operating unit 61. Furthermore, when the operating unit 61 is operated to descend, the tilting on-off valve 38 is set to an open state based on a control signal from the operating unit 61.

[0086] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 25a2 of the tilting cylinder-rod mechanism 25Y via the first gas flow path 41, the second tilting switching valve 32A2Y, and the third gas flow path 43. Also, a portion of the liquid in the liquid chamber 25a1 of the tilting cylinder-rod mechanism 25Y is returned to the liquid chamber 33a2 of the tilting converter 33Y via the liquid flow path 51 by the gas pressure of the gas chamber 25a2.

[0087] Meanwhile, a portion of the gas in the gas chamber 33a1 of the tilting converter 33Y is discharged to the atmosphere from the tank 34 via the second gas flow path 42, the tilting first switching valve 33A1Y and the fourth gas flow path 44A2 due to the liquid pressure in the liquid chamber 33a2.

[0088] As a result, the rod 25c of the tilting cylinder-rod mechanism 25Y moves in the retracted direction. That is, the tilting cylinder-rod mechanism 25Y tilts the pillow section 15 backward via the tilting mechanism YA. Also, the pillow section 15 moves in the direction of lowering the patient's head while supporting it due to the fluid pressure from the tilting converter 33Y.

[0089] The medical chair device 1A according to the first embodiment of the present invention comprises a chair body (backboard portion 14), a headrest (pillow portion 15) movably attached to the chair body, a cylinder-rod mechanism 25 interposed between the chair body and the headrest, and a converter 33 that converts gas pressure from a pressure source 31 into liquid pressure, and the cylinder-rod mechanism 25 is extended by the liquid pressure supplied from the converter 33. Therefore, the examination chair apparatus 1A can reduce operating noise and discomfort to the patient compared to when an electric motor is used to move the pillow section 15. Furthermore, the examination chair apparatus 1A can be made smaller and less expensive compared to when a hydraulic pump is used to move the pillow section 15. Furthermore, the examination chair apparatus 1A can better support the patient's head compared to when gas pressure is used to move the pillow section 15. Furthermore, the examination chair apparatus 1A can achieve low costs by using the pressure source of a dental examination unit as the pressure source 31.

[0090] The medical chair device 1A includes a first connection path (first gas flow path 41 and second gas flow path 42) that connects the pressure source 31 and the converter 33 so that gas can flow between them, a switching valve (first switching valve 32A1 and second switching valve 32A2) provided in the first connection path, and a second connection path (third gas flow path 43) that connects the switching valve and the cylinder-rod mechanism 25 so that gas can flow between them, and the cylinder-rod mechanism 25 is retracted by the gas pressure supplied from the pressure source 31 through the switching valve and the second connection path. Therefore, the medical chair device 1A uses gas pressure from the pressure source 31 when moving the pillow portion 15 in the retracting direction, so that the pillow portion 15 can be moved in both the extending direction and the retracting direction with a simple structure.

[0091] The medical chair apparatus 1A includes a tank 34 for receiving gas discharged from at least one of the converter 33 and the cylinder-rod mechanism 25. Therefore, the medical chair apparatus 1A can separate the liquid contained in the discharged gas in the tank , and reduce the amount of liquid discharged to the outside of the tank .

[0092] The medical chair device 1A comprises a linear motion mechanism XA that supports the headrest so that it can move linearly relative to the chair body, and a tilting mechanism AB that supports the headrest so that it can tilt relative to the chair body. The cylinder-rod mechanism 25 comprises a linear motion cylinder-rod mechanism 25X that linearly moves the headrest via the linear motion mechanism XA, and a tilting cylinder-rod mechanism 25Y that tilts the headrest via the tilting mechanism YA. The converter 33 comprises a linear motion converter 33X connected to the linear motion cylinder-rod mechanism 25X so that fluid can flow therethrough, and a tilting converter 33Y connected to the tilting cylinder-rod mechanism 25Y so that fluid can flow therethrough. Therefore, the examination chair apparatus 1A improves the degree of freedom in the position (and posture) of the headrest (pillow portion 15), and can hold the patient's head in an appropriate manner.

[0093] In the medical chair apparatus 1A, the switching valve is composed of two three-port solenoid valves. Therefore, the examination chair apparatus 1A realizes a circuit using a three-port solenoid valve, which is relatively cheaper than a four-port solenoid valve, and therefore can achieve low costs.

[0094] Second Embodiment Next, a medical chair apparatus according to a second embodiment of the present invention will be described, focusing on the differences from the medical chair apparatus 1A according to the first embodiment.

[0095] 9 and 10, a medical chair apparatus 1B according to a second embodiment of the present invention includes a direct acting mechanism XB instead of the direct acting mechanism XA. The direct acting mechanism XB includes a direct acting selector valve 32BX and a fourth gas flow path 44B instead of the direct acting first selector valve 32A1X, the direct acting second selector valve 32A2X, and the fourth gas flow paths 44A1 and 44A2.

[0096] The medical chair device 1B also includes a tilting mechanism YB instead of the tilting mechanism YA. The tilting mechanism YB includes a tilting selector valve 32BY and a fourth gas flow path 44B instead of the tilting first selector valve 32A1Y, the tilting second selector valve 32A2Y, and the fourth gas flow paths 44A1 and 44A2.

[0097] <Gas flow path> As shown in FIG. 10, the fourth gas flow path 44B connects the switching valve 32B and the tank 34 so that gas can flow therethrough.

[0098] The switching valve 32B is interposed between the first gas flow path 41, the second gas flow path 42, the third gas flow path 43, and the fourth gas flow path 44B. The switching valve 32B is a four-port solenoid valve that can be switched between a first state and a second state described below.

[0099] The first state is a state in which the first gas flow path 41 and the second gas flow path 42 are connected to each other so that gas can flow therethrough, and the third gas flow path 43 and the fourth gas flow path 44 are connected to each other so that gas can flow therethrough.

[0100] The second state is a state in which the first gas flow path 41 and the third gas flow path 43 are connected to each other so that gas can flow therethrough, and the second gas flow path 42 and the fourth gas flow path 44 are connected to each other so that gas can flow therethrough.

[0101] <Example of operation> Next, an example of the operation of the medical chair device 1B will be described in the order of linear movement and tilting of the pillow portion 15.

[0102] <Linear motion: Stop> First, the stopped state of the pillow part 15 will be described as the state before and after the operation of the pillow part 15 in the direct acting direction. As shown in Fig. 10, when the operating part 61 (see Fig. 2) is not operated, the direct acting on-off valve 38 is in a closed state. Also, when the operating part 61 is not operated, the direct acting switching valve 32BX is in a first state.

[0103] Here, the liquid pressure in the liquid chamber 33a2 of the direct drive converter 33X is maintained by closing the direct drive on-off valve 38. Also, the gas pressure in the gas chamber 33a1 of the direct drive converter 33X becomes equal to the liquid pressure in the liquid chamber 33a2.

[0104] Meanwhile, the liquid pressure in the liquid chamber 25a1 of the direct acting cylinder-rod mechanism 25X is maintained by closing the on-off valve 38. Also, the gas pressure in the gas chamber 25a2 of the direct acting cylinder-rod mechanism 25X becomes equal to the liquid pressure in the liquid chamber 25a1.

[0105] As a result, the direct-acting cylinder-rod mechanism 25X maintains the position of the pillow portion 15 in the direct-acting direction. In addition, the pillow portion 15 appropriately supports the patient's head by the fluid pressure from the direct-acting converter 33X.

[0106] <Linear motion: rising (extension)> 11, when the operating unit 61 (see FIG. 2) is operated for lifting, the direct acting switching valve 32BX is set to the first state based on a control signal from the operating unit 61. Also, when the operating unit 61 is operated for lifting, the direct acting on-off valve 38 is set to the open state based on a control signal from the operating unit 61.

[0107] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 33a1 of the direct drive converter 33X via the first gas flow path 41, the direct drive switching valve 32BX, and the second gas flow path 42. Also, a portion of the liquid (liquid pressure) in the liquid chamber 33a2 of the direct drive converter 33X is supplied to the liquid chamber 25a1 of the direct drive cylinder-rod mechanism 25X via the liquid flow path 51 by the gas pressure of the gas chamber 33a1.

[0108] Meanwhile, a portion of the gas in the gas chamber 25a2 of the direct acting cylinder-rod mechanism 25X is discharged to the atmosphere from the tank 34 via the third gas flow path 43, the direct acting switching valve 32BX and the fourth gas flow path 44B due to the liquid pressure in the liquid chamber 25a1.

[0109] As a result, the rod 25c of the direct-acting cylinder-rod mechanism 25X moves in the extension direction. That is, the direct-acting cylinder-rod mechanism 25X raises the pillow part 15 via the direct-acting mechanism XB. The pillow part 15 also moves in a direction that lifts the patient's head while supporting it with the fluid pressure from the direct-acting converter 33X.

[0110] <Direct action: Downward (retraction)> 12, in a state in which the operating unit 61 (see FIG. 2) is operated for lowering, the direct acting switching valve 32BX is set to the second state based on a control signal from the operating unit 61. In addition, in a state in which the operating unit 61 is operated for lowering, the direct acting on-off valve 38 is set to the open state based on a control signal from the operating unit 61.

[0111] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 25a2 of the direct acting cylinder-rod mechanism 25X via the first gas flow path 41, the direct acting switching valve 32BX, and the third gas flow path 43. Also, a portion of the liquid in the liquid chamber 25a1 of the direct acting cylinder-rod mechanism 25X is returned to the liquid chamber 33a2 of the direct acting converter 33X via the liquid flow path 51 by the gas pressure of the gas chamber 25a2.

[0112] On the other hand, part of the gas in the gas chamber 33a1 of the direct drive converter 33X is discharged to the atmosphere from the tank 34 via the second gas flow path 42, the direct drive switching valve 33BX and the fourth gas flow path 44B due to the liquid pressure in the liquid chamber 33a2.

[0113] As a result, the rod 25c of the direct-acting cylinder-rod mechanism 25X moves in the retracted direction. That is, the direct-acting cylinder-rod mechanism 25X lowers the pillow part 15 via the direct-acting mechanism XB. The pillow part 15 also moves in the direction of lowering the patient's head while supporting it with the fluid pressure from the direct-acting converter 33X.

[0114] <Tilt: Stop> First, the stopped state of the pillow part 15 will be described as the state before and after the operation of the pillow part 15 in the tilting direction. As shown in Fig. 10, when the operating part 61 is not operated (see Fig. 2), the tilting opening / closing valve 38 is in a closed state. Also, when the operating part 61 is not operated, the tilting switching valve 32BY is in a first state.

[0115] Here, the liquid pressure in the liquid chamber 33a2 of the tilting converter 33Y is maintained by closing the tilting on-off valve 38. Also, the gas pressure in the gas chamber 33a1 of the tilting converter 33Y becomes equal to the liquid pressure in the liquid chamber 33a2.

[0116] Meanwhile, the liquid pressure in the liquid chamber 25a1 of the tilting cylinder / rod mechanism 25Y is maintained by closing the on-off valve 38. Also, the gas pressure in the gas chamber 25a2 of the tilting cylinder / rod mechanism 25Y becomes equal to the liquid pressure in the liquid chamber 25a1.

[0117] As a result, the tilting cylinder-rod mechanism 25Y maintains the position in the linear motion direction of the pillow part 15. Furthermore, the pillow part 15 appropriately supports the patient's head by the fluid pressure from the direct drive converter 33Y.

[0118] <Tilt: Forward tilt (extension)> 11, when the operating unit 61 (see FIG. 2) is operated to tilt forward, the tilting switching valve 32BY is set to a gas supply state based on a control signal from the operating unit 61. Also, when the operating unit 61 is operated to tilt forward, the tilting opening / closing valve 38 is set to an open state based on a control signal from the operating unit 61.

[0119] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 33a1 of the tilting converter 33Y via the first gas flow path 41, the tilting switching valve 32BY, and the second gas flow path 42. Also, a portion of the liquid (liquid pressure) in the liquid chamber 33a2 of the tilting converter 33Y is supplied to the liquid chamber 25a1 of the tilting cylinder-rod mechanism 25Y via the liquid flow path 51 by the gas pressure of the gas chamber 33a1.

[0120] Meanwhile, a portion of the gas in the gas chamber 25a2 of the tilting cylinder / rod mechanism 25Y is discharged to the atmosphere from the tank 34 via the third gas flow path 43, the tilting switching valve 32BY, and the fourth gas flow path 44B due to the liquid pressure in the liquid chamber 25a1.

[0121] As a result, the rod 25c of the tilting cylinder-rod mechanism 25Y moves in the extension direction. That is, the tilting cylinder-rod mechanism 25Y tilts the pillow section 15 forward via the tilting mechanism YB. Also, the pillow section 15 moves in a direction that lifts the patient's head while supporting it with the fluid pressure from the tilting converter 33Y.

[0122] <Tilt: Retroversion (retraction)> 12, when the operating unit 61 (see FIG. 2) is operated for rearward tilting, the tilting switching valve 32BY is set to the second state based on a control signal from the operating unit 61. When the operating unit 61 is operated for downward movement, the tilting opening / closing valve 38 is set to the open state based on a control signal from the operating unit 61.

[0123] Here, the gas (gas pressure) supplied from the pressure source 31 is supplied to the gas chamber 25a2 of the tilting cylinder-rod mechanism 25Y via the first gas flow path 41, the tilting switching valve 32BY, and the third gas flow path 43. Also, a portion of the liquid in the liquid chamber 25a1 of the tilting cylinder-rod mechanism 25Y is returned to the liquid chamber 33a2 of the tilting converter 33Y via the liquid flow path 51 by the gas pressure of the gas chamber 25a2.

[0124] On the other hand, a portion of the gas in the gas chamber 33a1 of the tilting converter 33Y is discharged to the atmosphere from the tank 34 via the second gas flow path 42, the tilting switching valve 33BY, and the fourth gas flow path 44B due to the liquid pressure in the liquid chamber 33a2.

[0125] As a result, the rod 25c of the tilting cylinder-rod mechanism 25Y moves in the retracted direction. That is, the tilting cylinder-rod mechanism 25Y tilts the pillow section 15 backward via the tilting mechanism YB. Also, the pillow section 15 moves in the direction of lowering the patient's head while supporting it with the fluid pressure from the tilting converter 33Y.

[0126] In the medical chair apparatus 1B according to the second embodiment of the present invention, the switching valve 32B is configured by a single four-port solenoid valve. Therefore, the examination chair apparatus 1B realizes a circuit using a single four-port solenoid valve, and therefore, the apparatus can be made compact.

[0127] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0128] 1A,1B Medical chair equipment 11 Base (chair body) 12 Seat part (chair body) 14 Back panel (chair body) 15 Pillow (headrest) 18 Pillow holding part 21 frames 23 Slide rail 25 Cylinder rod mechanism 25X Linear cylinder rod mechanism 25Y Tilting cylinder rod mechanism 32A1 First switching valve 32A1X Direct operated first switching valve 32A1Y First switching valve for tilting motion 32A2 Second switching valve 32A2X Direct operated first switching valve 32A2Y Second switching valve for tilting 32B Switching valve 32BX Direct operated switching valve 32BY tilting switching valve 33 Converter 33X Direct-acting converter 33Y tilt converter XA, XB linear motion mechanism YA,YB tilting mechanism

Claims

1. The chair body and a headrest attached movably to the chair body; a cylinder rod mechanism interposed between the chair body and the headrest; a converter that converts gas pressure from a pressure source into liquid pressure; Equipped with The cylinder rod mechanism extends by the hydraulic pressure supplied from the converter. A medical chair device characterized by:

2. a first connection path that connects the pressure source and the converter so as to be able to gas flow; a switching valve provided in the first connection line; a second connection passage that connects the switching valve and the cylinder-rod mechanism so as to allow gas to flow therebetween; Equipped with The cylinder rod mechanism is retracted by the gas pressure supplied from the pressure source through the switching valve and the second connection passage.

2. The medical chair apparatus according to claim 1.

3. a tank for receiving gas discharged from at least one of the converter and the cylinder-rod mechanism; 3. The medical chair apparatus according to claim 2.

4. a linear motion mechanism that supports the headrest so that the headrest can move linearly relative to the chair body; a tilting mechanism that supports the headrest tiltably relative to the chair body; In addition to providing The cylinder rod mechanism includes: a linear motion cylinder / rod mechanism that linearly moves the headrest via the linear motion mechanism; a tilting cylinder / rod mechanism that tilts the headrest via the tilting mechanism; Equipped with The converter includes: a direct drive converter connected to the direct drive cylinder / rod mechanism so as to be able to flow fluid therethrough; a tilt converter fluidly connected to the tilt cylinder-rod mechanism; Equipped with 2. The medical chair apparatus according to claim 1.

5. The switching valve is composed of two three-port solenoid valves.

3. The medical chair apparatus according to claim 2.

6. The switching valve is composed of a single four-port solenoid valve.

3. The medical chair apparatus according to claim 2.

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