JP3213155B2 - Dental clinic - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental examination table, and more particularly, to an automatic stop mechanism of a dental examination table having a tray table provided on a back plate.

[0002]

2. Description of the Related Art A first prior art is disclosed in
-97123. In this prior art, the chair and back plate are raised or lowered and the back plate is tilted with respect to the chair, and the base end of the arm is horizontal on the back plate regardless of the tilt position of the back plate. There is disclosed a dental examination table which is rotatably provided around a vertical axis and a tray table is supported at the free end of the arm so as to be rotatable about the vertical axis.

In such prior art, when the chair and back plate are lowered or the back plate is tilted downward, the arm or tray table comes into contact with an object such as an operator's leg or chair. However, since the structure for stopping the lowering operation of the chair and the back plate and the downward tilting operation of the back plate is not provided, these lowering operations cannot be stopped. Therefore, as long as the surgeon and assistant do not move the obstacles below the back plate, the arm and the tray table, the lowering operation continues,
There is a problem that safety is impaired.

A second prior art is disclosed in, for example,
No. 181155. In this prior art, an auxiliary member is connected to the chair and / or the back plate in a dental clinic where the chair and the back plate are raised or lowered, and the back plate is tilted with respect to the chair. Switch means is provided between the member and the chair or between the auxiliary member and the back plate, and when an obstacle comes in contact with the chair and / or the back plate, the switch means of the chair and / or the back plate is provided. A configuration that stops the operation is disclosed.

In the second prior art, the descending motion of the chair and the back plate can be stopped only when an obstacle comes in contact with the chair and the back plate. By the auxiliary member provided on the child and the backboard,
The configuration becomes complicated and large. Further, since the tray table is not provided on the back plate, even if an object comes into contact with the tray table or an arm connecting the tray table to the back plate, the lowering operation of the chair and the back plate cannot be stopped. There is a problem that.

A third prior art is disclosed in, for example, Japanese Utility Model Application Publication No.
No. 42217. In this prior art,
A hanger corresponding to the tray table of the present invention, which can be moved in the horizontal direction by an arm and is rotatable around a vertical axis, is provided on a unit body provided on one side of the examination table. The hanger is provided with a sensing member corresponding to the abutting member of the present invention and two microswitches for detecting the displacement of the sensing member. And the operation of the back plate is stopped.

In the third prior art, the hanger corresponding to the tray table of the present invention is provided not on the back plate but on the unit main body. Although an increase in complexity and size is avoided, it is not possible to detect the contact of the obstacle with the back plate and the chair, and the contact of the obstacle with the arm connecting the hanger and the unit body is not detected. Contact cannot be detected.

[0008]

In the above three prior arts, a tray table shown in the first prior art is provided with a sensing member and a micro switch shown in the third prior art, and a chair and a chair are provided. Although it is easily conceivable to stop the lowering operation of the chair and the back plate by detecting the contact of the obstacle accompanying the lowering of the back plate, an area where the contact of the obstacle can be detected by the sensing member is considered. Is extremely low, and it is impossible to stop the lowering operation of the chair and back plate by detecting the contact of an obstacle with the arm and other medical equipment provided in connection with the tray table. Have.

Accordingly, it is an object of the present invention to broadly detect an abutment of an obstacle on a tray table and other articles such as an arm and medical equipment provided therewith, and to provide a chair and / or back. An object of the present invention is to provide a dental couch with improved safety that can stop the lowering operation of the plate.

[0010]

SUMMARY OF THE INVENTION The present invention provides a seating chair on which a patient sits, a back plate which is tiltably connected to the seating chair, and a lifting drive for raising or lowering the sitting chair and the back plate. Means, a tilting drive means for tilting the back plate with respect to the chair,
The base plate has a base end on a back plate, which is rotatable around a vertical axis in a horizontal state regardless of the tilting position of the back plate, and is angularly displaceable upward from a horizontal position in a plane including the vertical axis. An arm connected to the arm, a tray table rotatably supported on the free end of the arm around a vertical axis, and provided on the lower surface of the tray table, when an object located below the tray table abuts. First stopping means for stopping the lowering operation of the lifting / lowering driving means and / or the tilting driving means; and an arm, wherein when the arm is pushed upward, the lowering operation of the lifting / lowering driving means and / or the tilting driving means is performed. Second stopping means for stopping, wherein the first stopping means comprises a plate-shaped abutting member suspended substantially parallel to the lower surface of the tray table at an interval, and a tray table of the abutting member. Change of interval And a first switching element for detecting the change of the gap between the contact member and the tray table is detected by the first switching element, the descending operation is stopped, and the contact member includes a medical device. The dental clinic is provided with a holder for holding the dentist.

[0011]

Further, the present invention is characterized in that a means for spring-biasing the contact member in a direction away from the tray table is interposed between the contact member and the tray table.

[0013]

Further, the present invention provides a seating chair on which a patient sits, a back plate which is tiltably connected to the seating chair, a lifting drive means for raising or lowering the sitting chair and the back plate, and a back plate. A tilt drive means for tilting the seat with respect to the chair, and a base end portion on the back plate, the base end being rotatable about a vertical axis in a horizontal state regardless of the tilt position of the back plate and including the vertical axis. An arm connected to the back plate so as to be angularly displaceable upward from a horizontal position in a plane, a tray table rotatably supported around a vertical axis at a free end of the arm, and provided on a lower surface of the tray table; First stopping means for stopping the lowering operation of the lifting / lowering driving means and / or the tilting driving means when an object located below the tray table comes in contact with the arm, and when the arm is pushed up Lifting drive means and / or A second stop means for stopping the lowering operation of the tilt drive means, wherein the first stop means is a plate-shaped contact member suspended substantially parallel to the lower surface of the tray table at intervals. A first switching element for detecting a change in the distance between the contact member and the tray table,
When a change in the gap between the contact member and the tray table is detected by the first switching element, the lowering operation is stopped, and the second stopping means is connected to the back plate so as to be rotatable around a vertical axis. A first hinge piece, a second hinge piece rotatably connected to the first hinge piece about a horizontal axis and to which the arm is fixed, and an operating piece pressed by the second hinge piece; A second switching element fixed to the first hinge piece by switching the on / off state by pressing the piece and releasing the pressed state;
When the operating piece of the second switching element is pressed by a hinge piece, the lowering operation is stopped.

Further, according to the present invention, the first hinge piece includes:
A means for regulating a lower limit position of the second hinge piece is provided.

[0016]

[0017]

[0018]

According to the present invention, a back plate is tiltably connected to a chair on which a patient sits, and these chairs and the back plate can be raised or lowered by means of a lifting drive means. Further, the back plate can be tilted with respect to the chair by tilt drive means. Therefore, a patient sitting on a chair should be examined by the surgeon with the upper body upright, that is, with the medical posture upright, or with the upper body almost horizontal, that is, with the medical posture horizontal. Can be.

An arm is provided on the back plate. This arm is kept horizontal regardless of the tilting position of the back plate, is rotatable about a vertical axis, and at any position around this vertical axis, from a horizontal position within a plane including the vertical axis. It can be angularly displaced upward. Therefore, when the chair and the back plate are lowered by the lifting / lowering drive means, or when the back plate is tilted downward by the tilt drive means, even if an obstacle comes into contact with the arm, the arm is moved from the horizontal position. It can be evacuated upward. Such an arm may be constituted by a single member, or may be constituted by a plurality of members.

At the free end of the arm, a tray table is supported rotatably about a vertical axis. On this tray table, a tray on which medicines necessary for medical treatment and various instruments are mounted is placed.

A first stopping means is provided on the lower surface of such a tray table. When an object located below the tray table comes into contact with the first stopping means, the first stopping means stops the lowering operation of the elevation driving means and / or the tilt driving means. That is, when only the lifting / lowering driving means is stopped, the backing chair stops the lowering operation together with the back plate while the back plate is kept at a fixed tilt position. When only the tilt drive means is stopped, the downward movement of the back plate is stopped while the chair is kept at a constant elevating position,
Further, when both the raising and lowering driving means and the tilting driving means are stopped, the lowering operation of the seat and chair together stops, and the lowering movement of the back plate stops.

The arm is provided with second stopping means. When the arm is pushed upward from the horizontal position, the second stop means is a lifting drive means or a tilt drive means,
Alternatively, the lowering operations of both the lifting drive unit and the tilt drive unit are stopped. In this way, when an obstacle comes into contact with the descending tray table, the first stopping means responds to stop the descending operation, and when the obstacle comes into contact with the descending arm, The second stopping means can stop the lowering operation in response. Therefore, even when the tray table and the arm are rotated around the vertical axis, when the tray table and the arm come into contact with an obstacle, the descending operation can be stopped, and safety is improved.

According to the present invention, the first stopping means detects a change in the interval of the contact member disposed on the lower surface of the tray table with respect to the tray table by the first switching element, and detects the change in the interval. Then, the lowering operation of the elevation drive means and / or the tilt drive means is stopped. Since the contact member is plate-shaped, it can be detected in a wide range below the tray table by one first switching element on both sides, and a wide range in the entire movable range of the tray table or the arm can be detected. By detecting contact with an object, it is possible to stop the lowering operation of the lifting drive unit and / or the tilt drive unit.

[0024]

According to the present invention, the contact member is provided with a holder for holding a medical device. Even when an obstacle comes into contact with such a holder, it is possible to stop the lowering operation of the elevation drive unit and / or the tilt drive unit. Furthermore, according to the present invention, spring biasing means is provided between the contact member and the tray table. Even if an obstacle comes into contact with the contact member by the spring urging means and the contact member is displaced toward the tray table, the contact member is reliably returned in a direction away from the tray table,
It is possible to prevent a malfunction such as the first stop unit being kept off.

According to the present invention, the second stopping means is connected to the back plate so as to be rotatable around a vertical axis.
A second hinge piece is rotatably connected to the hinge piece about a horizontal axis, the second hinge piece is fixed to an arm, and a second switching element is attached to the first hinge piece. Therefore, when the descending arm contacts the obstacle and is pushed upward, the second hinge piece is angularly displaced with respect to the first hinge piece, and the operating piece of the second switching element is pressed by the second hinge piece. The switching mode changes. Since the arm is connected to the back plate in this manner, even if the arm is rotated about a vertical axis, there is no possibility that an external force acts on the operating piece of the second switching element due to the rotation of the arm. (2) Damage to the switching element is prevented, and the upward movement of the arm is reliably detected regardless of the rotational position of the arm, and the lowering operation of the elevation drive means and / or the tilt drive means is stopped. Can be done.

Further according to the present invention, the first hinge piece is provided with means for regulating the lower limit position of the second hinge piece.
Since the arm is fixed to the second hinge piece, the lower limit position of the arm can be regulated by the lower limit position regulating means, whereby the arm and the tray table are rotatably positioned around the vertical axis at a desired height. Can do it.

[0028]

[0029]

[0030]

FIG. 1 is a side view showing a dental examination table 1 according to an embodiment of the present invention, FIG. 2 is a front view of the dental examination table 1 as viewed from the left side of FIG. 1, and FIG. FIG. 2 is a plan view of the dental examination table 1 as viewed from above. The dental examination table 1 of the present embodiment includes a chair 4 on which a patient 3 sits, a back plate 5 that is connected to the chair 4 automatically or manually so as to be tiltable in the directions of arrows A1 and A2, A double-acting hydraulic cylinder 6 for lifting, which is lifting drive means for manually lifting the chair 4 and the back plate 5 in the direction of arrow B1 or lowering in the direction of arrow B2;
A double-acting hydraulic cylinder for tilting 7 which is tilting driving means for tilting the back plate 5 with respect to the chair 4 in the directions of the arrows A1 and A2;
The base end 8 is rotatable around the vertical axis 9 in a horizontal state regardless of the tilted position of the back plate 5 on the back plate 5 and upwards from the horizontal position in one plane including the vertical axis 9. C1,
An arm 10 connected to be freely angularly displaceable in the direction C2, a tray table 14 rotatably supported on a free end portion 11 of the arm 10 around a vertical axis 13;
A first stop means 15 provided on the lower surface of the lower part, for stopping the lowering operation of the raising / lowering double-acting hydraulic cylinder 6 and / or the tilting double-acting hydraulic cylinder 7 when an object located below the tray table 14 abuts. And a second stop means 16 for stopping the lowering operation of the lifting double-acting hydraulic cylinder 6 and / or the tilting double-acting hydraulic cylinder 7 when the arm 10 is pushed upward.

The patient 3 is seated on the chair 4 with both legs up and sitting on the back plate 5 standing up as shown by the imaginary line 17 in FIG. Is chair 19
By operating the foot pedal 20, the back plate 5 is tilted in the direction of the arrow A1 from the state indicated by the imaginary line 17, and the patient 3 is in a horizontal treatment position in a state of lying down. 3 is a plan view of FIG.
When the position is at 2 o'clock, the surgeon 18 performs the medical care operation at a position before and after 11:00 with the trunk center line almost aligned with the work point of the patient 3, that is, the oral cavity. At this time, the tray table 14 is located at a position indicated by an imaginary line 14a in FIG. 3 and FIG. 5 to be described later, and is drawn in the direction of arrow D1 to a distance sufficiently accessible to the medical instrument on the tray table 14. In this state, the patient 3 is treated. In this case, the foot pedal 20 is operated so that the working point of the patient 3 is at a position where the operator 18 can clearly recognize it, and the tilting position of the back plate 5 in the directions of the arrows A1 and A2 and the seat chair 4 and the back plate The up / down position in the direction of arrow B1, B2 of 5 is adjusted. In addition, depending on the treatment site, the operator 18 moves to the position indicated by the imaginary line 21 in FIG. 3 while the patient 3 is standing, and the instrument is moved as indicated by the imaginary line 14b in FIGS. The tray table 14 is turned around the vertical axis 13 in the direction of the arrow E2 so that
At the same time, the patient may be drawn in the arrow D2 direction to perform medical treatment. Also in this case, the medical care site is the operator 1 of the virtual line 21.
The foot pedal 20 is operated to adjust the height of the patient 3 so that the patient 8 can be clearly recognized.

The height of the chair 4 and the back plate 5 or the angle of the back plate 5 are set to one or several types so that the patient 3 can be properly positioned for treatment according to the treatment site.
During the treatment operation, the chair 4 and the back plate 5 can be automatically raised and lowered to a predetermined desired height or the back plate 5 can be automatically tilted to a predetermined desired angle automatically by selection. A position control switch 100 may be provided.

The automatic position control switch 100
Is a button switch, a touch sensor, or the like, for example, in addition to a portion corresponding to the shoulder of the back plate 5, a tray arm, a foot controller, or any other device may be provided at an appropriate place, and may be a switch independent of the treatment table. Good.

Thus, regardless of whether the medical treatment position of the patient 3 is standing or horizontal, the tray table 14
Must be drawn to a range where the instrument 23 can be easily reached. However, at this time, the surgeon 18 adjusts the height of the patient 3 centering on the treatment site of the patient 3, and thus the surgeon 18 The arm 10 and the tray table 14 that have descended may come into contact with the leg 24 of the arm. As described above, when the leg 24 of the surgeon 18 as an object disposed below the arm 10 and the tray table 14 comes into contact with the arm 10 or the tray table 14 during the lowering operation, the first stopping means 15 described above. Or second stopping means 16
Thus, the lowering operation of the double-acting hydraulic cylinder 6 for lifting and / or the double-acting hydraulic cylinder 7 for tilting can be stopped.

FIG. 4 shows the arm 10 and the tray table 1.
4 is a sectional view, and FIG. 5 is a plan view near the arm 10 and the tray table 14. The arm 10 is provided with a tilting axis 26 from one side of the back plate 5 to the chair 4 of the back plate 5.
It is connected to a connection shaft 25 projecting in the axial direction parallel to (see FIG. 3). The connecting shaft 25 is connected to arrows A1, A2 of the back plate 5 by a link mechanism (not shown) built in the back plate 5.
Regardless of the tilt position in the direction, the tray table 14 is rotated with respect to the back plate 5 so that the tray table 14 is always horizontal.

At the free end of the connecting shaft 25, the base end 8 of the arm 10 is rotatable about the vertical axis 9 in the directions of arrows D1 and D2 by the first shaft 27 having the vertical axis 9. Be linked. The tray table 16 is connected to the free end portion 11 of the arm 10 by a second shaft 28 having a vertical axis 13 so as to be rotatable around the vertical axis 13 in the directions of arrows E1 and E2. The second shaft 28 is controlled by a knob 29
It can be positioned and fixed to the free end 11 of the arm 10 at an arbitrary position in the vertical direction along the vertical axis 13.
The upper portion of the second shaft 28 is supported by a bearing 30, and the bearing 30 is fixed to the lower surface 31 of the tray table 14.

The tray table 14 includes an aluminum support plate 33 to which the bearing 30 is fixed, and a synthetic resin table body 34 mounted on and supported by the support plate 33.
And a tray 35 mounted on the table body 34 to which, for example, a filth holder, a medicine bottle holder, and a gauze holder are attached. Such a tray table 14
Is provided with the first stopping means 15 described above.

FIG. 6 is a partial sectional view showing a state in which the first stopping means 15 and the tray table 14 are attached. The first stop means 15 includes a plate-shaped aluminum contact member 36 suspended substantially parallel to the lower surface 31 of the tray table 14 with a space L1 therebetween. A microswitch 37 that is a first switching element that detects a change in the interval L1. The contact member 36 is suspended from the lower surface 31 of the tray table 14 by a plurality of (six in this embodiment) dampers 38. The microswitch 37 is fixed to a lower end of an inverted L-shaped mounting member 39. The operating piece 40 of this micro switch 37
Is in contact with the upper surface 41 of the contact member 36. Therefore, when the contact member 36 is pushed upward from below in the direction approaching the tray table 14, that is, the distance L1
When the value changes in a direction to decrease, the on / off state is switched. Such a change in the signal of the microswitch 37 is guided to a control device (not shown) via the lead wire 43, and stops the lowering operation of the double-acting hydraulic cylinder 6 for lifting and / or the double-acting hydraulic cylinder 7 for tilting.

The damper 38 includes a piston rod 46 having one end in the axial direction fixed to the support plate 33 of the tray table 14 by a screw 44, and an annular flange 45 formed at the other end in the axial direction, and a contact member. 36, a bottomed right cylindrical casing 48 fixed by screws 47, a compression coil spring 49 stored in the casing 48, and a compression coil spring 49 stored in the casing 48 and urged by the compression coil spring 49. An annular retaining piece 50 is provided for retaining the flange 45 on the open end side of the casing 48.

By providing the damper 38 having such a configuration, when the contact member 36 descends and comes into contact with an obstacle, the impact can be reduced, and
The contact member 36 can be reliably returned to the initial position forming the interval L1.

As clearly shown in FIG. 5 described above, the contact member 36 is provided in the area between the vertical axis 13 and the peripheral edge on the side where the instrument 23 is disposed, and In the longitudinal direction (vertical direction in FIG. 5).

Referring to FIG. 4 again, the contact member 36 includes a generally U-shaped connector holder 51 and an instrument holder 5 which is a holder for holding a medical device.
3 are provided to protrude below the contact member 36. A socket 55 is fixed to the connector holder 51, and plugs 56 connected to tubes 54 connected to the respective instruments 23 are detachably mounted on the socket 55. A tube 57 is connected to the socket 55, and a flexible hose 58 is connected together with the lead wire 43.
And is connected to the back surface of the back plate 5.

FIG. 7 is an enlarged sectional view of the vicinity of the second stop means 16, and FIG. 8 is an exploded perspective view of the second stop means 16.
The second stopping means 16 includes a first hinge piece 60 to which a microswitch 59 as a second switching element is attached and which is connected to the back plate 5 so as to be rotatable around a vertical axis 9.
A second hinge piece 63 rotatably connected to the first hinge piece 60 about the horizontal axis 61; and a first hinge piece 60, 63 rotatably connected to the first hinge piece 60 about the horizontal axis 61. And a third shaft 64. Micro switch 59
Is attached and fixed to the first hinge piece 60 as described above. This micro switch 59 has an operating piece,
The operating piece is pressed by the second hinge piece 63, and the micro switch 59 switches on / off state by this pressing and release of the pressed state.

The first hinge piece 60 is formed substantially in a step shape, and the first hinge piece 60 is disposed on the side of the connecting shaft 25.
5, a second portion 66 formed integrally with one side of the first portion 65 and a third portion 67 integrally formed with the second portion 66. The first portion 65 includes a first shaft 27.
Is inserted and stopped by a taper pin (not shown). The first shaft 27 has a straight columnar shaft portion 68 and a flange portion 69 integrally formed between both ends of the shaft portion 68 in the axial direction. A thrust washer 70 is mounted. In a state where the thrust washer 70 is mounted, as shown clearly in FIG. 7 described above, the thrust washer 70 is inserted into an insertion hole 73 formed in the receiving portion 71 of the connection shaft 25, and protrudes downward from the insertion hole 73. After a thrust washer 74 made of synthetic resin and a truncated conical disc spring 75 are attached to the lower end of the shaft portion 68, two nuts 76 and 77 are screwed.

With such a configuration, the receiving portion 71 of the connecting shaft 25 is tightened with the nuts 76 and 77 so that the thrust washers 70 and 74 are interposed on both surfaces by the spring force of the disc spring 75. It is elastically held between the flange 69 and the disc spring 75. Therefore, the first hinge piece 60 connected to the first shaft 27 as described above.
Is a disc spring 75 extending upward along the vertical axis 9 of the first shaft 27.
Can be displaced against the spring force. With such a configuration, even when the arm 10 is pushed upward by a large force, the connecting shaft 25 and the back plate 5
The upward displacement of the arm 10 can be allowed by the compression deformation of the leaf spring 75 without a large force acting on the arm 10.

A shaft hole 78 through which the third shaft 64 is inserted is formed in the second portion 66 of the first hinge piece 60.

The third portion 67 of the first hinge piece 60 is formed with a screw hole 79 substantially parallel to the insertion hole 75, and the screw hole 79 restricts the lower limit position of the second hinge piece 69. Adjustment bolt 80 is screwed. An end face of the adjustment bolt 80 protruding upward from the screw hole 79 abuts on the lower surface of the second hinge piece 63, and the second hinge piece 6
3 is supported. The microswitch 59 is fixed to one side surface 83 of the third portion 67 with screws or the like.

The second hinge piece 63 has a plate-like base 85 fixed to the arm 10 by a plurality of screws 84, and is formed integrally with the base 85, and has a shaft hole 86 through which the third shaft 64 is inserted. A pair of bearing portions 8 each formed with 87
8, 89. Between the bearings 88 and 89, the first
Fitting recess 90 into which second portion 66 of hinge piece 60 fits
Is formed. With the second portion 66 fitted into the fitting recess 90, each of the shaft holes 86 and 87 and the second portion 66
The shaft holes 78 communicate with each other on the same axis, and the third shaft 64 is inserted so that the first hinge piece 60 and the second hinge piece 63 are rotatably connected to each other.

A longitudinal end of a pressing spring 93 is fixed to the lower surface 81 of the second hinge piece 63 by a screw 91. The other end of the holding spring 93 is connected to the first hinge piece 66.
Abuts on the lower surface 94 of the third portion 67. When the arm 10 is lifted upward, the pressing spring 93 causes the second hinge piece 63 to move the third hinge 6 against the first hinge piece 60.
4 is resiliently urged in the direction of arrow F2 around the horizontal axis 61 to surely return the arm 10 to the horizontal position.

FIG. 9 is a block diagram for explaining a schematic configuration for controlling the double-acting hydraulic cylinder 6 for raising and lowering and the double-acting hydraulic cylinder 7 for tilting. The two micro switches 37 and 59 described above are connected to control means 95 realized by a CPU (Central Processing Unit) or the like.
Each time the switching mode of each of the microswitches 37 and 59 changes, the input signal to the control means 95 switches from a low level to a high level. When the operating piece of the microswitch 59 is pressed by the second hinge piece 63, the input signal to the control means 95 switches from low level to high level. At least one of microswitches 37 or 5
When the input signal from the control unit 9 becomes high level, each of the driving means 96 and 97 outputs a valve closing signal to each of the solenoid valves 98 and 99 at the same time so that the hydraulic source 90 supplies the double-acting hydraulic cylinders 6 and 7 from the hydraulic source 90. Switch the supply direction of pressure oil. When at least one of the micro switches 37 and 59 is switched from the low level to the high level in this way, the lowering operations of the double-acting hydraulic cylinders 6 and 7 are stopped.

As another embodiment of the present invention, the first stopping means 15 may be realized by a pressure-sensitive sheet switch attached to the lower surface of the contact member 36.
Further, instead of the micro switch 37 of the first stopping means 15, an optical detecting element such as a photo interrupter is attached to the mounting member 3.
9, a contact member 36 is provided with a shielding member that can be inserted into an optical path between a light emitting element and a light receiving element constituting the photointerrupter, and an obstacle comes into contact with the contact member 36. When pushed up, the light emitted from the light emitting element may be blocked to change the switching mode.

As described above, according to the present invention, the contact member 3
6 is detected by a microswitch 37 as a first switching element,
0 is detected by the microswitch 59, which is the second switching element, when the obstacle comes into contact with the obstacle 10 and the obstacle 10 is detected when the arm 10 and the tray table 14 are lowered, regardless of the rotational position. Can reliably be detected, thereby improving safety.

In the above embodiment, the first and second stopping means 15 and 16 are provided on the dental treatment table. However, as another embodiment of the present invention, the first and second stopping means 15 and 16 are provided. Only one of them may be provided.

[0054]

According to the present invention, when an object located below the tray table comes into contact with the first stopping means when the chair and the back plate are lowered or the back plate is tilted and lowered, the first stop is performed. The means stops the lowering operation of the elevation drive means and / or the tilt drive means. That is, when only the lifting / lowering driving means is stopped, the backing plate stops the lowering operation together with the backing plate while the back plate is kept at a fixed tilting position, and when only the tilting driving means is stopped, The child stops the downward tilting operation of the back plate while being kept at the constant raising and lowering position, and when both the raising and lowering driving means and the tilting driving means are stopped, the lowering operation of the seat chair stops, The downward tilting operation of the back plate stops.

The arm is provided with second stopping means. When the arm is pushed upward from the horizontal position, the second stop means is a lifting drive means or a tilt drive means,
Alternatively, the lowering operations of both the lifting drive unit and the tilt drive unit are stopped. In this way, when an obstacle comes into contact with the descending tray table, the first stopping means reacts to stop the descending operation, and when the obstacle comes into contact with the descending arm, The second stopping means can react and stop the lowering operation. Therefore, even when the tray table and the arm are rotated about the vertical axis, when the obstacle comes into contact with the obstacle, the descending operation can be stopped, and the safety is improved.

Further, according to the present invention, the first stopping means detects a change in the interval of the contact member arranged on the lower surface of the tray table with respect to the tray table by the first switching element, and detects the change in the interval. Then, the descending operation of the traveling drive means and / or the tilt drive means is stopped. Since the contact member is plate-shaped, a wide detection area can be obtained below the tray table by a single first switching element, and contact with an obstacle can be detected in a wide range, and the lifting drive means And / or the descending operation of the tilt drive means can be stopped.

[0057]

Further, according to the present invention, the contact member is provided with a holder for holding a medical device. Even when an obstacle comes into contact with such a holder, it is possible to stop the lowering operation of the elevation drive unit and / or the tilt drive unit. Further, according to the present invention, spring biasing means is provided between the contact member and the tray table. Even if an obstacle comes into contact with the contact member by the spring urging means and the contact member is displaced toward the tray table, the contact member is reliably returned in the direction away from the tray table to prevent malfunction. be able to.

Further, according to the present invention, the second stopping means is connected to the back plate so as to be rotatable around a vertical axis.
A second hinge piece is rotatably connected to the hinge piece about a horizontal axis, the second hinge piece is fixed to an arm, and a second switching element is attached to the first hinge piece. Therefore, when the descending arm contacts the obstacle and is pushed upward, the second hinge piece is angularly displaced with respect to the first hinge piece, and the operating piece of the second switching element is pressed by the second hinge piece. The switching mode changes. Since the arm is connected to the back plate in this manner, even if the arm is rotated about a vertical axis, there is no possibility that an external force acts on the operating piece of the second switching element due to the rotation of the arm. (2) Damage to the switching element is prevented, and the upward movement of the arm is reliably detected regardless of the rotational position of the arm, and the lowering operation of the elevation drive means and / or the tilt drive means is stopped. Can be done.

Further, according to the present invention, the first hinge piece is provided with means for regulating the lower limit position of the second hinge piece.
Since the arm is fixed to the second hinge piece, the lower limit position of the arm can be regulated by the lower limit position regulating means, whereby the arm and the tray table are rotatably positioned around the vertical axis at a desired height. Can do it.

[0061]

[0062]

[Brief description of the drawings]

FIG. 1 is a side view showing a dental examination table 1 according to an embodiment of the present invention.

FIG. 2 is a front view of the dental examination table 1 as viewed from the left side of FIG.

FIG. 3 is a plan view of the dental examination table 1 as viewed from above in FIG.

FIG. 4 is a cross-sectional view of the arm 10 and the tray table 14.

FIG. 5 is an enlarged plan view showing the vicinity of an arm 10 and a tray table 14.

FIG. 6 is a partial cross-sectional view showing a specific configuration of the first stopping means 15;

FIG. 7 is a partial cross-sectional view showing a specific configuration of the second stopping means 16;

FIG. 8 is an exploded perspective view of the second stopping means 16;

FIG. 9 is a block diagram showing a schematic configuration for controlling a double-acting hydraulic cylinder for lifting 6 and a double-acting hydraulic cylinder for tilting 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dental examination table 3 Patient 4 Chair 5 Back plate 6 Double-acting hydraulic cylinder for raising and lowering 7 Double-acting hydraulic cylinder for tilting 8 Base end 9, 13 Vertical axis 10 Arm 11 Free end 14 Tray table 15 First stop means 16 second stopping means 17, 21 virtual line 18 operator 20 foot pedal 23 instrument 24 leg 25 connecting shaft 27 first shaft 28 second shaft 31 lower surface 36 contact member 37, 59 micro switch 38 damper 51 connector holder 53 Instrument holder 54, 57 Tube 60 First hinge piece 61 Horizontal axis 63 Second hinge piece 64 Third axis 80 Adjusting bolt 95 Control means 96, 97 Drive means 98, 99 Solenoid valve

Claims (4)

(57) [Claims] 1. A chair on which a patient sits, a back plate which is tiltably connected to the chair, a lifting drive means for raising or lowering the chair and the back plate, and a back plate. A tilt drive means for tilting the chair, a base end of the back plate, and a flat surface including the vertical axis rotatably around a vertical axis in a horizontal state regardless of the tilt position of the back plate; An arm connected to the back plate so as to be angularly displaceable upward from the horizontal position; a tray table rotatably supported around a vertical axis at a free end of the arm; and a tray table provided on the lower surface of the tray table. First stopping means for stopping the lowering operation of the lifting / lowering driving means and / or the tilting driving means when an object located below is brought into contact with the arm; and a lifting / lowering drive provided when the arm is pushed up. Means and / or tilt drive A second stop means for stopping the lowering operation of the step, wherein the first stop means is a plate-shaped contact member suspended substantially parallel to the lower surface of the tray table at intervals, and the contact member A first switching element for detecting a change in the distance between the tray table and the tray table. When the first switching element detects a change in the gap between the contact member and the tray table, the lowering operation is stopped, The contact members include
A dental clinic, wherein a holder for holding medical equipment is provided. 2. The dental practice according to claim 1, wherein a means for urging the contact member in a direction away from the tray table is interposed between the contact member and the tray table. Stand. 3. A seating chair on which a patient sits, a back plate which is tiltably connected to the seating chair, elevating drive means for raising or lowering the seating chair and the backing plate, A tilt drive means for tilting the chair, a base end of the back plate, and a flat surface including the vertical axis rotatably around a vertical axis in a horizontal state regardless of the tilt position of the back plate; An arm connected to the back plate so as to be angularly displaceable upward from the horizontal position; a tray table rotatably supported around a vertical axis at a free end of the arm; and a tray table provided on the lower surface of the tray table. First stopping means for stopping the lowering operation of the lifting / lowering driving means and / or the tilting driving means when an object located below is brought into contact with the arm; and a lifting / lowering drive provided when the arm is pushed up. Means and / or tilt drive A second stop means for stopping the lowering operation of the step, wherein the first stop means is a plate-shaped contact member suspended substantially parallel to the lower surface of the tray table at intervals, and the contact member A first switching element for detecting a change in the distance between the tray table and the tray table, and when the first switching element detects a change in the gap between the contact member and the tray table, the lowering operation is stopped; The two stopping means include a first hinge piece rotatably connected to a back plate about a vertical axis, and a second hinge connected to the first hinge piece so as to be rotatable about a horizontal axis and to which the arm is fixed. A second switching element having an operating piece pressed by the second hinge piece, switching the on / off state by pressing the operating piece and releasing the pressed state, and fixed to the first hinge piece. Including When said operating piece of the second switching element is pressed by a second hinge piece, dental treatment table, characterized in that stopping the downward movement. 4. The dental examination table according to claim 3, wherein the first hinge piece is provided with means for regulating a lower limit position of the second hinge piece.