JP6015955B2 - Chair lifting device and dental treatment chair - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chair lifting apparatus and dental treatment chair, and in particular, a chair lifting apparatus including a column extending in the vertical direction and a column guide arranged outside the column and connected to the chair, and the chair lifting device. Relates to a chair for dental treatment.

This type of dental treatment chair has a contour seat, with a backrest and an armrest on one end of the contour seat, and a leg rest on the other end. be able to.
In addition, the dental treatment chair is configured to be movable up and down and up and down so that the surgeon can easily treat the patient. For example, Patent Document 1 discloses a technology of an elevating device that supports the lower side of a contour sheet and moves a dental treatment chair along the vertical direction.

  FIG. 7 is a cross-sectional view of an essential part for explaining an example of a conventional lifting device, and the lifting device has a column 120 and a column guide 130 formed in a cylindrical shape having a quadrangular sectional view. The column 120 is fixed on the base 107 and extends along the vertical direction (direction perpendicular to the paper surface in FIG. 7). The column guide 130 is disposed outside the column 120 and can be moved in the vertical direction with respect to the column 120 by the power of a drive unit (not shown) using, for example, an electric cylinder or hydraulic pressure.

The column guide 130 holds the arm unit 106 connected to a chair (not shown), and the arm unit 106 and the chair move in the vertical direction as the column guide 130 moves up and down.
The column guide 130 includes a metal bearing 135 that abuts on the outer peripheral surface (hereinafter referred to as the raceway surface 122) of the column 120, and the outer peripheral surface (also referred to as a rolling surface) of the bearing 135 and the raceway surface. Each bearing 135 is in strong contact with the raceway surface 122 so that there is no gap with the bearing 122. Thereby, shaking of a chair can be suppressed.

JP 2003-235876 A

However, since the column 120 is tightened by the bearing 135, rolling fatigue occurs on the raceway surface 122, and surface-origin type damage starting from an indentation or a crack may occur. This breakage causes a shock and abnormal noise when the chair is raised and lowered, and causes anxiety to the patient. Therefore, the column 120 needs to be replaced.
On the other hand, when replacing the column 120, the chair is removed from the column guide 130 or the column guide 130 is removed from the column 120, so that a large work space for placing the removed chair or column guide or a long-time work is required. The replacement work becomes large because it is necessary. In addition, there is a problem that a large amount of money is required to replace the entire support.

Here, in order to avoid this large-scale replacement work, it is conceivable to use a resin roller instead of a metal bearing, but the required strength is not obtained because the force for tightening the column is reduced, There are problems such as the chair becoming easy to shake.
In addition, for example, it is conceivable to use a precision-formed slide rail installed on a machine tool for the raceway surface, but the manufacturing cost of the chair increases.

  The present invention has been made in view of the above-described circumstances, and minimizes shaking of the chair accompanying the movement of the patient, thereby extending the life of the chair while avoiding large-scale replacement work and cost increase. It is an object of the present invention to provide a chair lifting device and a dental treatment chair equipped with the chair lifting device.

  In order to solve the above-mentioned problems, a first aspect of the present invention is a chair provided with a column that is formed in a square shape in cross section and extends along the vertical direction, and a column guide that is disposed outside the column and connected to the chair. The supporting column has four corner portions chamfered at the four corners of the outer peripheral surface thereof and opposed to each other in the diagonal direction of the supporting column, and a rail that is detachably provided at the corner portion. The guide is characterized by having a bearing provided at a position facing the rail to move the column guide in the vertical direction.

  The invention according to claim 2 is characterized in that the support guide has a guide fixing bolt for securing a gap between the outer peripheral surface of the bearing and the rail when the rail is replaced.

  The invention of claim 3 is characterized in that the guide fixing bolt is screwed into the support guide in a direction in which the tilting posture of the support guide with respect to the support is corrected.

  A fourth aspect of the present invention is a dental treatment chair equipped with the chair lifting device according to any one of the first to third aspects.

  According to the present invention, the bearing rail is detachably provided at the corner portion of the support column, and it is only necessary to replace this rail. As a result, it is possible to provide a long-life chair that prevents damage to the column due to rolling fatigue while avoiding large-scale replacement work and cost increase.

It is a perspective view for demonstrating one Embodiment of the dental treatment chair carrying the raising / lowering device of the chair of this invention. It is a perspective view for demonstrating the structure of the raising / lowering apparatus shown in FIG. It is a perspective view of the support | pillar guide shown in FIG. It is sectional drawing of the support | pillar shown in FIG. 2, and a support | pillar guide. It is a perspective view for demonstrating the clearance gap by rotation of the eccentric shaft shown in FIG. FIG. 4 is a cross-sectional view taken along line VI-VI shown in FIG. 3. It is principal part sectional drawing for demonstrating an example of the conventional raising / lowering apparatus.

Hereinafter, the lifting device and the dental treatment chair of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view for explaining an embodiment of a dental treatment chair equipped with the chair lifting apparatus of the present invention, and the dental treatment chair is viewed from the diagonally rear left side.
The dental treatment chair 1 has a contour seat 2 above the base 7, a backrest 3 and an armrest 4 on one end side of the contour seat 2, and a leg rest (illustrated) on the other end side of the contour seat 2. Are omitted).

The work table 8 can be arranged on the side of the dental treatment chair 1, and various instruments 10 are held by the holder 9. Further, on the side of the dental treatment chair 1, a spitton 11 incorporating a chair lifting / lowering device of the present invention is erected on a base 7.
The lifting device is connected to the support portion 5 via, for example, an L-shaped arm portion 6 in plan view, and the support portion 5 supports the lower side of the contour sheet 2.

FIG. 2 is a perspective view for explaining the structure of the lifting device shown in FIG. 1, and the above dental treatment chair is viewed from the diagonally right front with reference to the position where the patient is sitting.
Each of the lifting devices has a column 20 and a column guide 30 which are formed in a cylindrical shape having a quadrangular sectional view. The support column 20 is not a cast product that requires an initial cost, but is manufactured from, for example, a general-purpose square pipe, and is fixed on the base 7 using bolts 21 and extends in the vertical direction.

  The support column 20 has four flat surface portions 22 formed to be wide, and the space between the adjacent flat surface portions 22 in the horizontal direction is chamfered. Specifically, the support column 20 has four corner portions 23 whose four corners of the outer peripheral surface are chamfered by, for example, milling. Each corner portion 23 is formed narrower than the flat portion 22, faces the diagonal direction of the support column 20, and extends along the vertical direction. Each corner portion 23 is provided with a rail 24 that forms a raceway surface of the bearing 35.

  The rail 24 is made of, for example, a steel material that has been polished after quenching, is elongated, and extends in the vertical direction. For example, the rail 24 can be fixed near the upper end or the lower end with screws 25 and is detachably provided at the corner portion 23. Thus, since the rail 24 is provided in the corner part 23 of the square-shaped support | pillar 20, compared with the case where the rail 24 is provided in the plane part 22, a rigid structure can be obtained.

  For example, a hydraulic pump 13 and an oil tank 14 are installed on the base 7, and the cylinder pipe 15 can move up and down along the rod rod 16 in accordance with an opening / closing operation of a solenoid valve (not shown). . The cylinder pipe 15 and the column guide 30 are connected by a cylinder pipe receiver 47, and the column guide 30 is movable in the vertical direction with respect to the column 20 by the reciprocation of the cylinder pipe 15. Note that the column guide may be moved in the vertical direction using an electric motor, a ball screw, or the like.

  The column guide 30 is arranged outside the column 20 and has four guide surface portions 31A, 31B, 31C, 31D facing the flat portion 22 of the column 20, and four guides facing the corner portion 23 and the rail 24 of the column 20. The guide surface portions 31A to 31D and the guide corner portions 32 are alternately arranged in the horizontal direction. In FIG. 2, for example, the guide surface portion 31 </ b> A that holds the arm portion 6 with the four arm portion mounting bolts 33 with hexagonal holes and the adjacent guide surface portion 31 </ b> D are visible, whereas the guide surface portion 31 </ b> B, Although 31C is not visible, as will be described later, the guide surface portion 31B is positioned next to the guide surface portion 31A and faces the guide surface portion 31D with the support column 20 interposed therebetween. Further, the guide surface portion 31C faces the guide surface portion 31A across the support column 20, and is connected to the cylinder pipe receiver 47 with, for example, four bolts with hexagonal holes.

  FIG. 3 is a perspective view of the column guide shown in FIG. 3, the illustration of the bearing 35 and the like in FIG. 2 is omitted, but FIG. 3 (A) is a perspective view seen from the left side of FIG. 2, and FIG. 3 (B) is seen from the rear side of FIG. FIG. 3B is a perspective view seen from almost the same direction as FIG. FIG. 3C is a perspective view seen from the right side of FIG. 4 is a cross-sectional view of the strut and the strut guide shown in FIG. 2, and is a cross-sectional view taken along the line IV-IV in FIG.

  The arm portion 6 described with reference to FIG. 2 is formed so as to be attachable by four arm portion mounting bolts 33 on the guide surface portion 31A shown in the right front of FIG. 3A and the left side of FIG. 4, and this guide surface portion 31A. Is connected to the support portion 5 shown in FIG. 3A is positioned on the right back side in FIG. 3B, and the left back side in FIG. 3C. Is not visible.

  As shown in FIG. 3, an installation hole 34 is formed in each guide corner 32 through the outer peripheral surface and inner peripheral surface of the column guide 30. For example, two installation holes 34 are provided in the vicinity of the upper end and the vicinity of the lower end of the guide corner 32, and the column guide 30 has a total of eight installation holes 34. Metal bearings 35 shown in FIG. 4 can be arranged in the installation holes 34, respectively. In addition, each installation hole 34 communicates with the shaft holes 37 and 38 that rotatably support the eccentric shaft 39 and the straight shaft 40 of FIG.

  Specifically, the left and right ends of the guide surface portion 31B shown in the left front of FIG. 3A (corresponding to the right front of FIG. 3B and the upper side of FIG. 4) are connected to the guide corner 32, respectively. As shown in FIG. 4, the shaft holes 38 are provided in these two guide corners 32 so as to intersect the installation holes 34, and the straight shaft 40 can be rotatably supported. The straight shaft 40 is loosely fitted to the bearing 35 in the installation hole 34. Further, screw holes 41 are formed on both sides of the installation hole 34 communicating with the shaft hole 38 to communicate the outer peripheral surface of the column guide 30 and the shaft hole 38, and the shaft fixing screw 42 is screwed into the screw hole 41 so that the straight shaft If it contacts with 40, rotation of the straight axis | shaft 40 will be controlled. The shaft fixing screw 42 is more preferably a hexagon socket head cap bolt similar to the arm mounting bolt 33 or the like.

  Also, the left and right ends of the guide surface portion 31D shown on the left front side of FIG. 3C (corresponding to the lower side of FIG. 4) are respectively connected to the guide corner portion 32. As shown in FIG. A shaft hole 37 is provided at the corner 32 so as to intersect the installation hole 34, and the eccentric shaft 39 can be rotatably supported. Thus, the eccentric shaft 39 is provided on the guide surface portion 31D, and maintenance can be easily performed by removing the cover from the front of the spit.

  The eccentric shaft 39 is provided with an appropriate preload subjected to torque management, and ensures the life of the bearing and the rail while suppressing the swing of the chair. For example, with respect to the central axis of the tip 39a and the like, The eccentric portion 39 b is partially eccentric, and the eccentric portion 39 b is loosely fitted to the bearing 35 in the installation hole 34. Further, screw holes 41 are formed on both sides of the installation hole 34 communicating with the shaft hole 37, and the outer peripheral surface of the column guide 30 and the shaft hole 37 are communicated with each other. When contacted with 39, the rotation of the eccentric shaft 39 is restricted.

  Thus, the straight shaft 40 is provided at the two guide corners 32 that are connected in the horizontal direction to the one guide surface 31B shown in the right front of FIG. 3B (corresponding to the upper part of FIG. 4). Each of the four bearings 35 is supported. On the other hand, there are a total of four eccentric shafts 39 provided at two guide corners 32 that are horizontally connected to one guide surface part 31D shown in the left front of FIG. 3C (corresponding to the lower part of FIG. 4). The bearings 35 are respectively supported. If only the four bearings on one side of the column guide are supported by the eccentric shaft as in this embodiment, an increase in manufacturing cost can be suppressed as compared to the case where all the bearings are supported by the eccentric shaft. Further, the center of the support column and the center of the support column do not shift.

  As shown in FIG. 3, for example, screw holes 45 are formed in the guide surface portions 31 </ b> C and 31 </ b> D so as to penetrate the outer peripheral surface and the inner peripheral surface of the column guide 30. For example, two screw holes 45 are provided near the upper end and the lower end near the center of the guide surface portions 31C and 31D, and the column guide 30 has a total of four screw holes 45. In order to counter the weight of the chair (also referred to as uneven load), the guide fixing bolts 46 shown in FIG. 6 can be screwed into the screw holes 45, respectively. The guide fixing bolt 46 is more preferably a hexagon socket head cap bolt similar to the arm portion mounting bolt 33 or the like.

FIG. 5 is a perspective view for explaining a gap due to rotation of the eccentric shaft shown in FIG.
When using the dental treatment chair, all the bearings 35 are brought into contact with the rails 24 so that there is no gap between the outer peripheral surface of the bearings 35 and the rails 24. In particular, as shown in FIG. 5A, the bearing 35 concentric with the eccentric portion 39 b is also brought into strong contact with the rail 24. Thereby, the support | pillar guide 30 can be guided to the rail 24, and can move to the up-down direction with respect to the support | pillar 20. As shown in FIG.

On the other hand, when it is desired to replace the four rails 24 provided in the corner portion 23 of the support column 20, after the eccentric shaft 39 is rotated, the posture of the support column guide 30 is secured using the guide fixing bolt 46.
Specifically, for example, when the current position of the column guide 30 is secured by hydraulic pressure, the shaft fixing screw 42 is loosened, and then the eccentric shaft 39 concentric with the tip 39a is rotated, as shown in FIG. The contact between the bearing 35 supported by the eccentric shaft 39 and the rail 24 is released. When the four eccentric shafts 39 are rotated, the four bearings 35 on one side of the column guide 30 are separated from the two opposing rails 24.

  As a result, the column guide 30 is tilted, and the gap between the upper side of the guide surface portions 31C and 31D and the upper side of the column 20 is narrowed, while the gap between the lower side of the guide surface portions 31C and 31D and the lower side of the column 20 is wide. However, the four guide fixing bolts 46 are screwed into the respective screw holes 45 of the guide surface portions 31C and 31D, and the tips of the guide fixing bolts 46 are brought into contact with the flat surface portion 22 of the column 20 as shown in FIG. The tilting posture of the column guide 30 relative to 20 is corrected to the posture before the eccentric shaft 39 rotates.

In the step of correcting the posture of the column guide 30, a clearance is secured between the bearing 35 supported by the eccentric shaft 39 and the facing rail 24, and the rail 24 facing the bearing 35 supported by the straight shaft 40. The gap is also secured.
Subsequently, if the screws 25 located near the upper end and the lower end of these four rails 24 are removed, respectively, it is possible to extract and replace only the rails 24 while leaving the column 20 on the base 7.

  As described above, the rail 24 is detachably provided on the corner portion 23 of the support column 20, so that a large-scale replacement operation such as replacement of the entire support column is not required. Further, only the rail 24 needs to be replaced, and the cost can be reduced as compared with the case where the entire support column is replaced. Therefore, it is possible to provide a long-life dental treatment chair that prevents the column from being damaged due to rolling fatigue while avoiding large-scale replacement work and cost increase.

Further, since the guide fixing bolt 46 secures a gap between the outer peripheral surface of the bearing 35 and the rail 24, the rail can be replaced more quickly than when the rail is replaced after the chair is removed from the support guide.
Further, as the tilting posture of the column guide 30 is corrected with the guide fixing bolt 46, a clearance between the outer peripheral surface of the bearing 35 and the rail 24 can be secured, which also contributes to facilitating the rail replacement work.

The eccentric shaft 39 is originally intended to extend the life of the bearings and rails while suppressing the shaking of the chair. However, the tilting posture of the column guide 30 easily occurs as the eccentric shaft 39 rotates. Therefore, it also functions as a trigger for rail replacement.
Further, in the case of a dental treatment chair, it has a large contour seat, a backrest, a legrest, etc. in order to make the patient easy to treat, and the replacement work is particularly large and the rail of the present invention. The exchange effect is more beneficial.

In the above embodiment, an example using four eccentric shafts 39 has been described. However, for example, if the rail can be pulled out by utilizing the gap between the bearing 35 and the rail 24 by generating the hydraulic pressure to secure the column guide 30 and loosening the shaft fixing screw 42, it is possible to use all straight shafts. Is possible.
In the above embodiment, an example using four guide fixing bolts 46 has been described. However, the guide surface portions 31A and 31B are also provided with screw holes and screwed into the guide fixing bolts, and a total of eight guide fixing bolts are used. May be. Further, if a chair or the like is removed from the support guide, the rail can be replaced without attaching a guide fixing bolt.

DESCRIPTION OF SYMBOLS 1 ... Dental treatment chair, 2 ... Contour seat, 3 ... Backrest, 4 ... Abutment stand, 5 ... Support part, 6 ... Arm part, 7 ... Base, 8 ... Work table, 9 ... Holder, 10 ... Instrument 11 ... Spitton, 13 ... hydraulic pump, 14 ... oil tank, 15 ... cylinder pipe, 16 ... rod rod, 20 ... post, 21 ... bolt, 22 ... plane part, 23 ... corner part, 24 ... rail, 25 ... Screws, 30 ... column guides, 31A, 31B, 31C, 31D ... guide surface portions, 32 ... guide corners, 33 ... arm mounting bolts, 34 ... installation holes, 35 ... bearings, 37, 38 ... shaft holes, 39 ... eccentricity Shaft, 39a ... tip, 39b ... eccentric part, 40 ... straight shaft, 41 ... screw hole, 42 ... shaft fixing screw, 45 ... screw hole, 46 ... guide fixing bolt, 47 ... cylinder pipe receiver.

Claims (4)

A lifting and lowering device for a chair comprising a column formed in a quadrangular shape in cross section and extending in the vertical direction, and a column guide arranged outside the column and connected to the chair,
The support column has four corners chamfered at the four corners of the outer peripheral surface and opposed in the diagonal direction of the support column, and a rail provided detachably on the corner unit,
The lifting / lowering device for a chair, wherein the support guide includes a bearing provided at a position facing the rail to move the support guide in a vertical direction.   2. The lifting device for a chair according to claim 1, wherein the column guide includes a guide fixing bolt that secures a gap between the outer peripheral surface of the bearing and the rail when the rail is replaced. 3.   The chair lifting / lowering device according to claim 2, wherein the guide fixing bolt is screwed into the column guide in a direction in which a tilting posture of the column guide with respect to the column is corrected.   A dental treatment chair comprising the chair lifting device according to any one of claims 1 to 3.

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