JP2013165746A - Liftable table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liftable table having a simple structure, easy to produce, having a light weight, and being inexpensive.SOLUTION: A liftable table includes at least four thread shaft holding components fixed on the lower surface of a top board, a thread shaft held by the thread shaft holding component and turned about the vertical axis, a nut portion threadedly put on the thread shaft, a fixed legs having an upper end provided with the nut portion, and a device for preventing the fixed leg from being turned relative to the thread shaft. The thread shaft holding component has a part located at a vertical position and having a vertical width corresponding to a driven toothed-pulley or driven sprocket, and the part is cut off on a side meshing with an endless toothed belt or endless chain, so that the endless toothed belt or endless chain is allowed to be mounted on all of the thread shaft holding components having been mounted on the lower surface of the top board.

Description

  The present invention relates to a table in which a top plate moves up and down by rotating a screw shaft built in a leg portion.

Conventionally, various structures have been invented as a table for raising and lowering the top plate. Among these, as a relatively simple mechanism, the top plate is raised and lowered by rotating a screw shaft built in the leg portion with a chain or a belt. Many things have been proposed.
For example, in Patent Document 1, a cylindrical fixed leg portion fixed to a frame body to which a top plate is attached, and a rotation that is rotatably fitted and supported in the fixed leg portion and protrudes from the upper end of the fixed leg portion. A bolt, a driven sprocket provided at a portion projecting from the upper end of the fixed leg of the rotating bolt, and transmitting the rotation to the rotating bolt; A structure is shown that includes a lifting leg portion that has a nut that is screwed to the rotating bolt and that moves up and down by the rotation of the rotating bolt.

  In Patent Document 2, a spiral body (screw shaft) that is screwed into a plurality of sprockets that are rotatably supported is attached to an upper receiving plate (or lower receiving plate) of a frame, and a ceiling member is attached to one end of the spiral body. A structure is shown in which the plates (or legs) are fixed together and all the sprockets are linked by a single endless chain.

  Further, Patent Document 3 has a structure in which an adjuster nut and an adjuster bolt are provided on each leg, a pulley that interlocks with the adjuster bolt is provided above the adjuster bolt, and an endless belt that drives the pulley is provided. It is shown.

  However, all of the structures shown in the above documents are complicated and manufactured by providing a driving force transmission structure such as a sprocket not directly on the top board but on the frame on which the top board is placed. It has the disadvantages of being difficult, heavy and costly.

JP 2001-231631 A JP-A-11-192127 Japanese Patent Laid-Open No. 11-70020

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lifting table that is easy to manufacture, lightweight, and inexpensive by simplifying the structure. is there.
Further, the table height is automatically and safely changed.

  A screw shaft holding component fixed to at least four locations on the lower surface of the top plate, a screw shaft held by the screw shaft holding component and rotating about a vertical axis, and a nut portion screwed into the screw shaft; In a lifting table provided with a fixed leg provided with each nut portion at the upper end and means for preventing the fixed leg from rotating with respect to the screw shaft, the rotation of the screw shaft is performed by each screw shaft. The driven toothed pulleys or driven sprockets mounted on the same axis are rotated by a common endless toothed belt or endless chain, and the driven toothed pulleys or driven sprockets are respectively connected via bearings. The screw shaft holding parts are held by each of the screw shaft holding parts, and the vertical position and the vertical width of the screw shaft holding parts corresponding to the driven toothed pulleys or driven sprockets are the driven toothed pulleys or the driven parts. By having a deficient portion on the side where the sprocket and the endless toothed belt or endless chain mesh with each other, the screw shaft holding part and the driven toothed pulley or driven sprocket are all attached to the lower surface of the top plate, A lifting table characterized in that the endless toothed belt or the endless chain can be mounted.

  Two idle pulleys or two idle sprockets are provided between two adjacent screw shaft holding components among the screw shaft holding components fixed to at least four locations of the top plate, and the two idle gears are provided. By providing a driving toothed pulley or driving sprocket between a pulley or two idle sprockets, the driven toothed pulley or driven sprocket held by the screw shaft holding component, the endless toothed belt or endless Each of the chain contact angles can be set in the vicinity of 90 °.

  The number of meshing teeth of the driving toothed pulley or driving sprocket according to claim 2 (the number of teeth meshing simultaneously with the toothed belt or chain) is 1 of the minimum number of meshing teeth of each driven toothed pulley or each driven sprocket. A lifting table in which when the endless toothed belt or endless chain is subjected to excessive driving tension, the tooth disengagement occurs exclusively on the side of the driving toothed pulley or driving sprocket. is there.

  Each of the fixed legs is cylindrical, and each of the fixed legs is attached to a common platform so as to be selectable between a rotatable state and a fixed state. Thus, by rotating the respective fixed legs, the nut portions provided at the upper ends of the respective fixed legs are rotated, and the screwing amounts of the respective screw shafts screwed into the respective nut portions can be adjusted equally. It is the raising / lowering table characterized by these.

  A sensor for measuring a distance using light reflection is attached to one of the top plate side or the fixed leg side, and a reflector plate is attached to the other of the top plate side or the fixed leg side via a rod-like body, An elevating table that measures and displays the height of a table by placing a distance sensor inside one end of a cylindrical body and arranging the reflector so as to move up and down the interior of the cylindrical body. is there.

  The driving toothed pulley or driving sprocket according to claim 2 is driven by a motor, and the position of the back side of the reflecting plate in the vicinity of the end of the cylindrical body on the side far from the distance sensor. And a limit switch for limiting the maximum height of the table is installed, and the minimum height of the table is further away from the distance sensor than the limit switch for limiting the maximum height of the table of the cylindrical body. It is a lifting table with limit switches that limit the height.

According to the first aspect of the present invention, since the screw shaft holding component including the screw shaft, the bearing, and the driven toothed pulley (or driven sprocket) is directly attached to the top plate, the structure is simple and the number of components is small. Thereby, a lightweight and low-cost lifting table can be provided.
In addition, since the endless toothed belt or the endless chain can be mounted after the screw shaft holding part is attached, assembly is also easy.
In addition, since the endless toothed belt or the endless chain is disposed directly under the top plate, a wide space can be secured at the lower portion of the top plate.

According to the second aspect of the present invention, the contact angle between the driven toothed pulley or driven sprocket and the endless toothed belt or endless chain held in the screw shaft holding part is set in the vicinity of 90 °. Therefore, the shape of the missing portion of the screw shaft holding component can be made one type.
As a result, a common screw shaft holding component can be used for the top plates of various sizes and shapes without being affected by the margin length of the belt or chain, further reducing the cost.

According to the third aspect of the present invention, the tooth belt (or chain) slippage (idling) that may occur when an excessive load is applied to the top plate is exclusively caused by the toothed pulley for driving ( Or, if the cause is removed (for example, if the load on the top plate is reduced), the normal state can be quickly restored.
If there is a tooth detachment on the driven toothed pulley (or driven sprocket) connected to the screw shaft, the amount of tooth detachment is generally not uniform between the multiple screw shafts. The amount of screwing becomes uneven and the top plate becomes non-horizontal, but such a phenomenon can be avoided.

According to the invention of claim 4, by making the fixed leg attached to the common foot stand temporarily rotatable, the screwing amount to each nut part of each screw shaft is adjusted to be equal, Thereafter, by fixing the fixed leg, the top plate can always move up and down in parallel to the leg base, and the sliding of the leg cover and the fixed leg becomes smooth.
Also, in the unlikely event that an excessive axial force is applied to a specific screw shaft, the driven toothed pulley (or driven sprocket) connected to this screw shaft causes tooth disengagement (idling) with respect to the toothed belt (or chain). Even when the parallelism between the pedestal and the top plate deteriorates, it can be readjusted easily.

  According to invention of Claim 5, the sensor which measures distance using reflection of light is attached to the end of a cylindrical body, and the reflecting plate which goes up and down according to the height of a table is provided in the inside of a cylindrical body. Thus, the distance sensor detects only the position of the reflector and is not affected by the surroundings, so that the height can be measured with high accuracy.

  According to the sixth aspect of the present invention, the limit switch for limiting the maximum height of the table by detecting the position of the back side of the reflecting plate in the vicinity of the end of the cylindrical body provided with the distance sensor on the side far from the distance sensor. Since the limit switch for limiting the minimum height by detecting the protrusion or the like installed on the fixed leg side can be disposed adjacently, two limit switches indispensable as a safety device can be compactly disposed.

Bottom view (partially sectional view) of a lifting table according to the present invention Sectional view of the leg of the lifting table according to the present invention (example in which the cross section of the guide cylinder is square) Sectional drawing of the screw shaft holding component by this invention (AA sectional drawing in FIG. 2) Sectional drawing of the screw shaft holding component by this invention (BB sectional drawing in FIG. 2) Sectional view of the leg of the lifting table according to the present invention (example in which the cross section of the guide tube is circular) Plan view of an elevating table according to the present invention (example with a circular guide tube and a leg stand) Front view of the lifting table according to the present invention (CC cross-sectional view of FIG. 6) Bottom view (partially sectional view) of L-shaped lifting table according to the present invention Table height measuring device according to the present invention

FIG. 1 is a bottom view (partially a sectional view) of a lifting table according to the present invention, and FIG. 2 is a leg sectional view.
The screw shaft holding component 2 is fixed with mounting bolts 42 at least at four locations on the top plate 1.
In the screw shaft holding component 2, an upper bearing 8a and a lower bearing 8b and a driven toothed pulley (or driven sprocket) 6 sandwiched between them are housed, and these three components are placed on the upper portion of the screw shaft 3. The extended cylindrical portion 3a passes through, and the driven toothed pulley (or driven sprocket) 6 and the cylindrical portion 3a are integrated by press-fitting a pin 17.

Since both the radial load due to the tension of the endless toothed belt (or endless chain) 7 and the thrust load that pushes the top plate 1 upward act on the upper bearing 8a, a deep groove ball bearing, an angular ball bearing, and a sliding bearing Select as appropriate.
In FIG. 2, the upward force applied to the screw shaft 3 acts on the driven toothed pulley (or driven sprocket) 6 via the pin 17 and pushes the inner ring of the bearing 8a via the small diameter shim 15b. The force is transmitted to the outer ring of the bearing 8a through the steel ball, and the top plate 1 is pushed through the large diameter shim 15a.

The lower bearing 8b receives a radial load similar to that of the upper bearing and a downward thrust load due to the weight of the fixed leg when the top plate is lifted for movement or the like.
In addition, in a table having a leg stand (for example, FIGS. 6 and 7), when a load is applied on the top plate of the portion overhanging from the leg portion, the pulling force is applied to the leg portion far from the place where the load is applied. Occur.
These thrust forces acting on the lower bearing 8b act on the driven toothed pulley (or driven sprocket) 6 via the pin 17, push the inner ring of the bearing 8b via the lower small-diameter shim 15b, The force is transmitted to the outer ring of the bearing 8b through the steel ball, and the bearing hole bottom 2c of the screw shaft holding component is pushed.

FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. 4 is a sectional view taken along line BB in FIG.
The vertical position and vertical width of the screw shaft holding component 2 corresponding to the driven toothed pulley (or driven sprocket) 6 are the driven toothed pulley (or driven sprocket) and the endless toothed belt (or endless chain). On the side to be meshed, there is a defective portion 9, and as a result, the portion that houses the upper bearing 8 a and the portion that houses the lower bearing 8 b are connected only by the portion 2 a where the material remains in a columnar shape.
The external force applied to the screw shaft holding component is mainly the tension (initial tension and drive tension) of the endless toothed belt (or endless chain) 7, and this endless toothed belt (or endless chain) passes through the missing part. Therefore, the distance from the point of application of force is small, and the bending moment applied to the columnar part 2a is relatively small.
Therefore, sufficient strength can be maintained in terms of design even if the missing portion 9 is made large.
In addition, with respect to a bending load applied to the legs when the table is pushed sideways, sufficient strength can be obtained by attaching a side plate to be described later using the female screw 16 or the like.

At the lower part of the screw shaft holding component 2, there is a quadrangular prism-shaped extending portion 2b, and a square pipe-like screw shaft cover 14 is fitted into this portion, and the screw shaft cover is used as a screw shaft holding component with a fixing screw 18. It is fixed.
The screw shaft 3 is screwed into the nut portion 4, and the nut portion 4 is fixed to the upper end of a square pipe-shaped fixing leg 5 that is thinner than the screw shaft cover 14, and the screw shaft cover 14 is fixed to the fixing leg. 5 is slidable in the vertical direction while fitting so as to prevent the fixed leg from rotating.
As another method for preventing the fixed leg 5 from rotating with respect to the screw shaft 3, a slit is provided in the vertical direction in the circular pipe-shaped screw shaft cover 14 fixed to the screw shaft holding component 2, and the slit is formed in the slit. A method (not shown) of fixing a fitting pin to the fixed leg 5 can be considered.

When screwing each screw shaft 3 into each nut portion 4, the endless toothed belt (or endless chain) 7 is sent in the direction in which the table descends while pressing all the screw shafts against the corresponding nut portions. Thus, the screwing amounts are made almost equal for all screw shafts.
If the screwing amount greatly varies with respect to each screw shaft, the nut portion 4 collides with the lower portion 2b of the screw shaft holding component at the lowest or highest table height, or the screw shaft 3 comes off the nut portion 4. There is a possibility that a problem may occur.
A nut 30 is fixed to the lower end of the fixed leg 5, and an adjuster bolt 31 is screwed into the nut 30 to correct some variation in the screwing amount of each screw shaft and unevenness of the floor on which the table is installed. To prevent the table from rattling.

In FIG. 1, two idle pulleys (or idle sprockets) 10 are arranged between two screw shaft holding parts 2 on the left side, and a drive toothed pulley (or drive pulley) is provided between the idle pulleys (or idle sprockets). By providing the sprocket 11, the contact angle α of all the driven toothed pulleys (or driven sprockets) 6 and the endless toothed belt (or endless chain) 7 can be set in the vicinity of 90 °.
In this case, each idle pulley (or idle sprocket) is attached at a position where the contact angle between the adjacent driven toothed pulley (or driven sprocket) and the endless toothed belt (or endless chain) is about 90 °.
In addition, the tooth of the toothed belt (or chain) with which the driving toothed pulley (or driving sprocket) meshes is the back side of the surface with which the driven toothed pulley (or driven sprocket) meshes, thereby driving teeth. The position of the attached pulley (or drive sprocket) can be arranged at a position that does not get in the way as much as possible.
As described above, if the defect portion 9 of the screw shaft holding component 2 is set so as not to interfere even at a contact angle of 100 °, for example, one type of screw shaft holding component can be used for the lifting table of various sizes and shapes. Can be used.

  In contrast to FIG. 1, without using an idle pulley, for example, a driving toothed pulley is arranged on the right side that is equidistant from two adjacent driven toothed pulleys on the left side, and the contact angle θ of the driving side pulley is set to If it is set to 90 °, the contact angle α on the driven side is 90 ° + 45 ° = 135 ° (asymmetric), and 90 ° + 45 ° + 45 in order to cope with this with one kind of symmetrical screw shaft holding parts. Defects 9 that can handle a contact angle of ° = 180 ° are required, and the strength and accuracy of the screw shaft holding component cannot be maintained.

The belt driving force required to rotate each driven-tooth pulley (or driven sprocket) is generated between the screw shaft 3 and the nut portion 4 connected to each driven-tooth pulley (or driven sprocket). Is the value obtained by dividing the torque to be driven by the pitch circle radius of the driven toothed pulley (or driven sprocket). The driving force that the driving toothed pulley (or driving chain) should apply to the belt is the same for all driven toothed pulleys. This is the total required belt driving force.
Here, for example, if at least four screw shafts have an axial load ratio of 10: 1: 1: 1 or more, the meshing teeth of the drive toothed pulley (or drive sprocket) 11 By reducing the number to 1.3 times or less of the minimum number of meshing teeth of each driven tooth pulley (or each driven sprocket) 6, the belt transmission force per tooth is always larger on the driving side, so it is excessive. Due to the load on the screw shaft, the tooth disengagement when the excessive driving tension is applied to the endless toothed belt (or endless chain) 7 is caused only on the driving toothed pulley (or driving sprocket) 11 side. become.
Here, the number of meshing teeth is the number of teeth with which the toothed pulley (or sprocket) and the toothed belt (or chain) mesh simultaneously, and is defined by the number of meshing teeth = the number of teeth × (contact angle / 360 °). .

  When an out-of-tooth occurs, an abnormal noise is generated, so that the user can recognize that an excessive load has been applied to the top plate, and the excessive-load can be quickly removed to eliminate the out-of-tooth. The At this time, if the tooth disengagement occurs only on the driving-side toothed pulley (or driving-side sprocket) side, the screwing amount of each screw shaft is kept the same, so that subsequent readjustment is not necessary.

FIG. 5 is an example in which the screw shaft cover 14 and the fixed leg 5 are formed in a cylindrical shape with respect to the structure of FIG. The fixed leg 5 is inserted into a fixed leg holding cylinder 23 fixed to the pedestal 12, and is fastened by a tightening screw 25 penetrating the fixed leg 5 and the fixed leg holding cylinder 23. Since the fixed leg holding cylinder 23 is provided with the slit 24, the fixed leg holding cylinder is elastically deformed to sandwich the fixed leg, so that the fixed leg does not rattle. Further, since the tightening screw 25 penetrates the fixed leg and the fixed leg holding cylinder, it is safe because the fixed leg will not come out even if the tightening force of the tightening screw is insufficient.
Further, if the fastening screw 25 is removed, the fixed leg 5 can be easily rotated, so that the screwing amount between the screw shaft 3 and the nut portion 4 can be adjusted for each leg.
One or two through holes on the fixed leg side that are provided to allow the fastening screw 25 to pass therethrough are sufficient. This is because, since the pitch of the screw shaft is about 2 mm, even if there is only one through hole, it can be fixed every 180 °, so that the variation in screwing amount can be adjusted within 1 mm for all screw shafts. .

Further, in FIG. 5, a rotating shaft 19 that penetrates the bearings 8 a and 8 b and the driven toothed belt (or driven sprocket) 6 is provided, and the screw shaft insertion hole 20 provided at the lower portion of the rotating shaft 19 is provided at the upper portion of the screw shaft. The provided cylindrical portion 3 a is inserted, the connecting pin 21 is penetrated, and the snap ring 22 is used.
By making the long screw shaft 3 attachable and detachable in this way, the screw shaft holding parts, the endless toothed belt (or endless chain), the motor, and other driving devices can be disassembled and easily transported. become.

FIG. 6 is a plan view of an elevating table having a circular guide cylinder 14 and a leg base 12 according to the present invention, and FIG. 7 is a front view thereof (CC cross-sectional view in FIG. 6).
In FIG. 6, the left and right footrests 12 are connected and integrated at the rear, but may be connected at the center depending on the application.
The electric motor 13 preferably has a reduction gear, and is preferably selected so that the rotational speed of the screw shaft is about 300 to 500 r / min.
The motor 13 and the idle pulley (or idle sprocket) 10 are fixed to the top plate by a mounting bolt 42 via a motor mounting part 40 and an idle pulley (or idle sprocket) mounting part 41, respectively. At this time, since the hole through which the mounting bolt 42 passes is a long hole 43, the initial tension of the endless toothed belt (or endless chain) can be adjusted to a predetermined value (see FIG. 1).

The side plate 26 is fixed by screwing the side plate mounting screw 27 into the female screw 16 provided on the side surface of the screw shaft holding component 2 and the female screw provided on the side plate mounting component 28 attached to the lower portion of the screw shaft cover 14.
As a result, the screw shaft covers 14 held by the screw shaft holding component 2 are connected to each other by the side plates, so that lateral rigidity (hardness of deformation when the top plate is pushed in the horizontal direction) is increased.
Moreover, when using as a desk, the vertical direction of the side plate 26a attached to the front surface is shortened to secure a space for a chair to enter.

FIG. 8 shows an example in which the lifting mechanism according to the present invention is applied to an L-shaped top plate.
The driven toothed pulley (or driven sprocket) held by the screw shaft holding component 2-L attached in the vicinity of the recess 1a of the top plate is an endless tooth on the opposite side of the other driven toothed pulley (or driven sprocket). It meshes with the attached belt (or endless chain).
Therefore, since the rotation direction is also reversed, the screw shaft and the nut portion that meshes with the screw shaft must be reversed.
If the line connecting the centers of the screw shaft holding parts is arranged at a right angle, the contact angle α of the driven toothed pulley (or driven sprocket) held by the screw shaft holding part 2-L is larger than 90 °. (About 95 ° in the state of FIG. 8).
Even for such a method of use, it is preferable to set the defect portion 9 so that the common screw shaft holding component 2 can be used.

FIG. 9 is a front view and a side cross-sectional view of a state in which upper and lower limit switches are attached to an apparatus that measures the table height using reflection of light.
A distance sensor 50 for measuring a distance using light reflection is attached to an upper end portion of a cylindrical body 53 having a rectangular cross section via a distance sensor attachment component 56, and the distance sensor attachment component is attached by a screw 57. Attach to the top plate 1.
On the other hand, the lower end portion of the rod-shaped body 51 having a circular cross section is inserted into the rod-shaped body mounting tube 59 fixed to the leg base 12 and connected by the pin 60, and the reflecting plate 52 is fixed to the upper end portion of the rod-shaped body 51.
With the above configuration, the distance between the distance sensor 50 and the reflecting plate 52 changes according to the elevation of the top plate, so that the height of the table can be calculated from the output voltage of the distance sensor.
In the above structure, an accurate distance can be measured because no disturbing object or light enters between the distance sensor and the reflection plate.
As the distance sensor, a sensor that detects a distance by measuring an infrared reflection angle, a sensor that detects a distance by measuring a reflection time of a laser beam, and the like can be used.

Further, a maximum height limiting limit switch 54 and a minimum height limiting limit switch 55 are mounted in the vicinity of the lower end of the cylindrical body 53, and the limit switch 54 is operated when the back surface 52a of the reflecting plate approaches, and the limit switch 55 Can be operated safely when the projection 58 fixed in the vicinity of the lower end of the rod-like body is approached.
Generally, in order to install a limit switch that limits the maximum table height, it is necessary to provide a separate mechanism that approaches when the fixed leg side and the top plate side are separated from each other, but it is incorporated into the table height measuring device as described above. Therefore, a structure with high cost performance can be achieved.

By detecting the height of the top board with the distance sensor as described above, not only the current height is calculated and displayed, but also the motor according to the difference from the current height when the target height is given. It is possible to perform control for calculating the time for driving the vehicle, detecting the difference from the target height again after the power is supplied for that time, and correcting the difference. According to this control method, even if the top plate hits an obstacle, the energization time of the motor is limited, so that accidents and damage are less likely to occur, and furthermore, when it is recognized that the change in height with respect to the energization time is small, It can be determined that an excessive load has been applied, and subsequent energization can be stopped.
Further, when calculating the energization time of the motor, it is preferable to measure and correct the environmental temperature. This is because grease is often enclosed in the reduction gearbox, and the mechanical efficiency of the gear differs depending on the temperature, which may affect the rotational speed.

The structure of the lifting table according to the present invention is not limited to a table, and can be used as a handrail for an indoor exercise equipment, for example. In this case, the height of the handrail can be adjusted according to the height of the user, and at the same time, the height of the monitor placed on the top plate and the reception of the wireless heart rate monitor attached to the bottom surface of the top plate There is also an effect of raising and lowering the height of the machine to an appropriate position.

DESCRIPTION OF SYMBOLS 1 Top plate 1a Top plate recessed part 2 Screw shaft holding part 2a Screw shaft holding part columnar part 2b Extension part 2c lower part of screw shaft holding part Bearing hole bottom part 2-L of screw shaft holding part Screw shaft holding component 3 Screw shaft 3a Cylindrical portion 4 provided on the upper portion of the screw shaft 4 Nut portion 5 Fixed leg 6 Pulley with driven tooth (or driven sprocket)
7 Endless toothed belt (or endless chain)
8a Upper bearing 8b Lower bearing 9 Deficient portion 10 of screw shaft holding part Idle pulley (or idle sprocket)
11 Driven toothed pulley (or drive sprocket)
12 Foot 13 Motor 14 Screw shaft cover 15a Large diameter shim 15b Small diameter shim 16 Side plate mounting female screw 17 Pin 18 Screw shaft cover fixing screw 19 Rotating shaft 20 Screw shaft insertion hole 21 Screw shaft connecting pin 22 Snap ring 23 Fixed leg holding tube 24 Slit 25 Fixed leg tightening screw 26 Side plate 26a Side plate 27 attached to the front side Side plate mounting screw 28 Side plate mounting component 30 Adjuster bolt mounting nut 31 Adjuster bolt 40 Motor mounting component 41 Idle pulley (or idle sprocket) mounting component 42 Mounting bolt 43 Long hole 50 Distance sensor 51 Rod-shaped body 52 Reflector plate 52a Back surface 53 of the reflector plate Cylindrical body 54 Limit switch (for maximum height restriction)
55 Limit switch (for minimum height restriction)
56 Distance sensor mounting part 57 Distance sensor mounting screw 58 Protrusion 59 Rod-shaped body mounting cylinder 60 Pin 61 Snap ring 62 Guide α Contact angle θ of driven toothed pulley (or driven sprocket) and endless toothed belt (or endless chain) Contact angle between toothed pulley (or drive sprocket) and endless toothed belt (or endless chain)

Claims (6)

  A screw shaft holding component (2) fixed to at least four locations on the lower surface of the top plate (1), a screw shaft (3) held by the screw shaft holding component and rotating about a vertical axis, and the screws Elevating / lowering provided with a nut part (4) screwed into the shaft, a fixed leg (5) provided with the nut part at the upper end, and means for preventing the fixed leg from rotating with respect to the screw shaft In the table, each screw shaft is rotated by rotating a driven toothed pulley or driven sprocket (6) mounted coaxially with each screw shaft by a common endless toothed belt or endless chain (7). The driven toothed pulleys or driven sprockets are held by the screw shaft holding parts via bearings (8a, 8b), respectively, and the driven toothed pulleys of the screw shaft holding parts or Compatible with driven sprockets The portion of the directional position and the vertical width has the missing portion (9) on the side where the driven toothed pulley or driven sprocket and the endless toothed belt or endless chain mesh with each other, so that the screw shaft holding component (2 And the endless belt or endless chain can be mounted after all the driven toothed pulley or driven sprocket (6) is attached to the lower surface of the top plate.   Two idle pulleys or two idle sprockets (10) between two adjacent screw shaft holding components among the screw shaft holding components (2) fixed to at least four locations of the top plate (1). And the driven toothed pulley held by the screw shaft holding part by providing the driving toothed pulley or the driving sprocket (11) between the two idle pulleys or the two idle sprockets. 2. The lifting table according to claim 1, wherein the contact angles of the driven sprocket (6) and the endless toothed belt or endless chain (7) can all be set in the vicinity of 90 °.   The number of meshing teeth (the number of teeth meshed simultaneously with the toothed belt or chain) of the driving toothed pulley or driving sprocket (11) according to claim 2 is that of each driven toothed pulley or each driven sprocket (6). When the number of meshing teeth is 1.3 times or less, the endless toothed belt or the endless chain (7) has a tooth disengagement when excessive driving tension is applied to the driving toothed pulley or driving sprocket ( 11. The lifting table according to claim 2, wherein the lifting table is formed on the side of 11).   Each of the fixed legs (5) has a cylindrical shape, and each of the fixed legs is attached to a common leg base (12) so that the rotatable state and the fixed state can be selected. The nuts (4) provided at the upper ends of the respective fixed legs are rotated by rotating the respective fixed legs in the state of being erected in the vertical direction, and the respective screws screwed into the respective nut parts The elevating table according to any one of claims 1 to 3, wherein the screwing amount of the shaft (3) can be adjusted equally.   A sensor (50) for measuring a distance using light reflection is attached to one of the top plate (1) side and the fixed leg (5) side, and a rod-like body is attached to the top plate side or the other of the fixed leg side. A reflector (52) is attached via (51), the distance sensor (50) is placed inside one end of the tubular body (53), and the reflector is arranged so as to move up and down the interior of the tubular body. 5. The lifting table according to claim 1, wherein the height of the table is measured and displayed. The driving toothed pulley or the driving sprocket (11) according to claim 2 is driven by a motor (13), and the cylindrical body (53) according to claim 5 on the side far from the distance sensor (50). A limit switch (54) for stopping the motor ascending operation when the back surface of the reflecting plate (52) approaches is provided in the vicinity of the end, and further, than the limit switch (54) of the cylindrical body. A lifting table characterized in that a limit switch (55) is installed to stop the lowering operation of the motor when a part of the fixed leg (5) side approaches the side far from the distance sensor (50).