JPH0147396B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a table lift device in which a link mechanism for raising and lowering a table is operated using a movable pulley. Conventionally, table lift devices have been operated using hydraulic pressure. As the hydraulic equipment was operated by the same system, the equipment costs for the hydraulic equipment were high, leading to high manufacturing costs. Therefore,
As a system that uses a movable pulley instead of a hydraulic system,
There is a table lift device described in Japanese Patent Application No. 57-61978 and Japanese Patent Application No. 57-62698. In this table lift device, as shown in FIGS. 1 and 2, a pair of links 4 and 7 are pivoted by a central shaft 9 so as to intersect with each other at their midpoints, and one end of the base 1 is mounted on both sides of the base 1. The lower end of the rotary link 4 is rotatably attached to the shaft 3, and the lower end of the movable link 7 is movably linked to the rails 2 provided on both sides of the base 1. Further, the upper end of the movable link 7 is rotatably attached to one end of the table 10 by a shaft 6, and the upper end of the rotary link 4 is attached along the rail portions 11 provided on both sides of the table 10. A movable pulley 18 is attached to the movable link 7, and a fixed pulley 14 is installed on the base 1, and a tow rope 1 is wound between the movable pulley 18 and the fixed pulley 14.
One end 17a of the moving link 7 is fixed to the base 1, and the other end 17b is wound around the winding drum 16 which is rotated by the electric motor 15 on the base 1.
The movable pulley 18 is attached to the center axis 9 of the rotating link 7.
An auxiliary pulley 12 is attached to hold down the tow rope 17 wound between the fixed pulley 14 and the fixed pulley 14 from above.

In this structure, the table 10 is raised when the rotary link 4 and the movable link 7 are laterally closed to each other about the central axis 9 at the lowest moving position of the table 10. In the initial stage of upward movement of the table 10, the rotation link 4
And since the moving link 7 is largely laid down,
Although the winding drum 16 requires a large winding force, the auxiliary pulley 12 holds down the tow rope 17 wound around the movable pulley 18 and the fixed pulley 14 from above at the lowest movable position of the table 10. The winding force at the beginning of the upward movement can be made smaller. However, when the table 10 rises to a certain extent, the tow rope 17 and the auxiliary pulley 12 become separated and cannot perform their functions satisfactorily.

Purpose An object of the present invention is to enable a moving pulley attached to at least one of a movable link and a rotating link to lift a tow rope wound between a pair of fixed pulleys, and to connect the tow rope to the movable pulley. To provide a table lift device capable of increasing the number of times of winding and lifting a table with a smaller winding force.

Structure of the Invention In order to achieve this object, the present invention has a movable pulley attached to at least one of the lowermost movable link and the rotary link, and a movable pulley mounted on a column erected on a base at both sides of the pulley. Fixed pulleys are installed, and a towing cable is wound between these fixed pulleys in a state that it is wrapped around the underside of this movable pulley, one end of this towing cable is fixed, and the other end is attached to a winding drum rotated by an electric motor. It was designed to be wrapped around.

Embodiment A first embodiment of the present invention will be described below with reference to FIGS. 3 and 4. A first stage rotation link 4 and a movable link 7 intersect in an X shape around a central axis 9 and are pivoted. The lower end of the rotary link 4 is rotatably attached to the shaft 3 on both sides of one end of the base 1, and the roller 8 at the lower end of the movable link 7 is attached to the rails 2 on both sides of the base 1. are linked so that they can move along. Also, both upper links 4 and 7 of the second stage are pivotally connected to each other in an X-shape by a central shaft 9, and the lower end of one of the upper links 7 of the second stage is relative to the upper end of the rotation link 4 of the first stage. The lower end of the other upper link 4 in the second stage is rotatably connected to the upper end of the moving link 7 in the first stage. The upper end of one of the upper links 7 of the second stage has a shaft 6 on both sides of one end of the table 10.
The roller 5 at the upper end of the other upper link 4 is rotatably attached to the table 1.
0 along the rail portions 11 on both sides.

A movable pulley 12 equipped with a plurality of pulleys that rotate independently of each other is attached to the central axis 9 of the first-stage rotation link 4 and the movable link 7. This movable pulley 12 is located at the upper end.
Fixed pulleys 14, which also have a plurality of pulleys that rotate independently of each other, are mounted on both sides of the vehicle. A tow cable 1 is connected between these fixed pulleys 14.
7 is wound around the lower side of this movable pulley 12 several times alternately, one end 17a of which is fixed to the base 1, and the other end 17b is secured to the base 1.
It is wound around a winding drum 16 which is rotated by an electric motor 15 above.

Next, the elevating and lowering action of the table lift device configured as above will be explained.

FIG. 3 shows the table 10 in its lowest position. In this state, the rotation link 4 and movable link 7 in the first stage and both upper links 4 and 7 in the second stage are opened laterally with respect to each other around the central axis 9, and their rollers 5 and 8 are rotated on the table. 10 and one end side of the rail portion 2 of the base 1. The movable pulley 12 is located below between both columns 13 and closer to one of the columns 13, and the traction cable 17 is unwound from the winding drum 16 of the electric motor 15.

When the load is placed on the table 10 at the lowest moving position and the tow rope 17 is wound up by the winding drum 16,
The movable pulley 12 uses the fixed pulley 14 as a fulcrum to support the tow rope 1.
7, and the roller 8 of the first stage rotation link 4 moves along the rail section 2 of the base 1 to the point A in FIG.
While being moved in the direction of the arrow, the roller 5 of one of the upper links 4 of the second stage is also moved in the direction of the arrow A in FIG. 3 along the rail portion 11 of the table 10.
The rotating link 4 and moving link 7 in the first stage and both upper links 4 and 7 in the second stage are laterally closed to each other about the central axis 9. Therefore, the table 10 rises.

In this structure, unlike the conventional example, by simply lifting the movable pulley 12, the first-stage rotary link 4 and the movable link 7 are closed to each other laterally around the central axis 9. , both links 4 and 7 close following the lifting, and the table 10 can be raised with a smaller winding force. Furthermore, when the tow rope 17 is wrapped around both fixed pulleys 14 once, the tow rope 17 is wrapped twice on the lower side of the movable pulley 12, so the number of times the tow rope 17 is wrapped around the movable pulley 12 is reduced. is increased, and the table 10 can be raised with an even smaller winding force. In this case, the closer the winding center angle of the movable pulley 12 (the angle that the contact part of the movable pulley 12 and the traction cable 17 makes with the center of the movable pulley 12) is 180 degrees, the more the winding drum 1
6, the winding force becomes smaller.

When the table 10 rises from the state shown in FIG. 3, the movable pulley 12 is moved diagonally upward as shown in FIG. The moving position is maintained. Note that the winding force of the winding drum 16 necessary for upward movement of the table 10 becomes smaller as the number of times the tow rope 17 is wound around the movable pulley 12 increases.

On the other hand, when the brake state of the winding drum 16 is released, the first and second stage links 4 and 7 are opened laterally to each other due to the weight of the table 10, and the movable pulley 12 moves diagonally downward. Tow rope 17
is unwound from the winding drum 16. Therefore, table 1
0 is lowered and stopped at the lowest position shown in FIG. Note that the descending speed of the table 10 is determined by the electric motor 1.
5.

The second embodiment shown in FIGS. 5 and 6 differs from the first embodiment in that the support 13 is moved to the base 1 by means of wheels 20.
Table 1
The support column 13 follows the movement of the movable pulley 12 when moving up and down. Therefore, the interval between both fixed pulleys 14 can be reduced, and the central angle of the winding of the movable pulley 12 can be reduced.
The third embodiment shown in FIGS. 7 and 8 is a third embodiment of the first embodiment described above. In the example, the movable pulley 12 is restricted to be able to move only up and down by a support 13 as a guide rail, and the lower end of the lowest rotary link 4 is also connected to the base 1.
The lowermost links 4 and 7 move away from and approach each other about the central axis 9 when the table 10 moves up and down. The advantages of this third embodiment are also similar to those of the second embodiment.

The present invention is not limited to the embodiment described in detail above, and the following configuration is also possible.

(b) In each of the above-mentioned embodiments, a pair of links 4 and 7 are pivoted from the center axis 9 so as to intersect with each other at their intermediate portions, and the X-shaped link is two-stage. It can also be applied to objects and objects of three or more steps. Particularly, when applied to a single-tier table, the support 13 is passed upward through the table 10 when the table 10 is in its lowest position, and a cover is attached to the table 10 so as to cover the support 13.

(B) In each of the embodiments described above, the movable pulley 12 is attached to the center axis 9 of the rotation link 4 and the movable link 7 of the first stage. Install it at any position above 9.

(c) In each of the embodiments described above, the electric motor 15 is connected to the base 1.
Although it is fixed above, an electric motor 15 is fixed to the table 10.

(d) In each of the embodiments described above, one end 1 of the tow rope 17
7a is fixed to the base 1, and as shown by the imaginary line in FIG. Fix it to the top of link 4.

Effects According to the present invention described in detail above, the movable pulley 12 attached to at least one of the movable link 7 and the rotary link 4 can be lifted by the traction device 17 wound between the pair of fixed pulleys 14. At the same time, there is an effect that the number of times the traction device 17 is wound around the movable pulley 12 is increased, and the table 10 can be raised with a smaller winding force.

[Brief explanation of drawings]

1 and 2 show a conventional example, FIG. 1 is a schematic diagram showing the table in the lowest position, FIG. 2 is a schematic diagram showing the table in the upper position, and FIGS.
5, 6, 7 and 8 respectively show the first embodiment, the second embodiment and the third embodiment, and FIGS. 3, 5 and 7 are the bottom FIG. 4, FIG. 6, and FIG. 8 are schematic diagrams showing the upward movement state of the table. Base...1, Rail part...2, Axis...3, Rotating link (upper link)...4, Roller...5, Axis...6, Moving link (upper link)...7, Roller... ...8, Central axis...9, Table...10, Rail part...11, Moving pulley...12, Support (guide rail)...13, Fixed pulley...14, Electric motor...
15. Winding barrel...16. Traction strategy...17.

Claims (1)

[Scope of Claims] 1. At least one stage of an X-shaped link mechanism is provided in which a pair of links 4 and 7 are pivoted by a central shaft 9 so as to intersect with each other in the middle part, and the lowest stage on the base 1 is provided. In a table lift device in which a lower end of a rotating link 4 and a lower end of a lowermost movable link 7 are supported, and a table 10 is supported at upper ends of a pair of uppermost links 7, the lowermost movable link 7 is supported. A movable pulley 12 is attached to at least one of the rotating links 4, fixed pulleys 14 are attached to the pillars 13 erected on the base 1 at positions on both sides of the movable pulley 12, and a fixed pulley 14 is installed between these fixed pulleys 14. The tow rope 17 is wound around the lower side of this movable pulley 12, and the tow rope 1
While fixing one end 17a of 7, the other end 17
A table lift device characterized in that b is wound around a winding drum 16 rotated by an electric motor 15. 2 The column 13 is fixed in position on the base 1, the lower end of the lowermost rotary link 4 is rotatably attached to the shaft 3 at one end of the base 1, and the lowermost movable link 7 The lower end of the link is movably linked along a rail section 2 provided on the base 1, and the upper end of one of the uppermost links 7 is rotatably attached to one end of the table 10 by a shaft 6. The table lift device according to claim 1, wherein the upper end of the other uppermost link 4 is movably linked along a rail portion 11 provided on the table 10. 3. The support 13 is movable along the base 1,
The lower end of the lowermost rotary link 4 is rotatably attached to a shaft 3 on one end side of the base 1, and the lower end of the lowermost movable link 7 is connected to a rail portion 2 provided on the base 1. The upper end of one of the uppermost links 7 is rotatably attached to a shaft 6 at one end of the table 10, and the upper end of the other uppermost link 4 is The table lift device according to claim 1, which is linked to be movable along a rail portion 11 provided on the table 10. 4 The column 13 is fixed in position on the base 1, and the lower end of the lowest rotary link 4 and the lower end of the lowest movable link 7 are movably linked together along the rail section 2 provided on the base 1. The upper end of one of the uppermost links 7 is rotatably attached to a shaft 6 at one end of the table 10, and the upper end of the other uppermost link 4 is attached to a rail section provided on the table 10. The movable pulley 12 is movably linked to a guide rail 13 erected and fixed on the base 1.
The table lift device according to claim 1, wherein only vertical movement is restricted by the table lift device. 5. The table lift device according to claim 4, wherein the guide rail is a support 13. 6 One end 17a of the tow rope 17 is fixed to the base 1, and the winding drum 16 around which the other end 17b is wound is installed on the base 1, and the movable pulley 12 is connected to the rotation link 4 and the movable link 7. The table lift device according to claim 1, which is attached to a central shaft 9 of the table lift device.