JPH06321494A - Motor-driven table lifter - Google Patents

Abstract

PURPOSE:To simplify the constituent mechanism of a motor-driven table lifter by moving a ramp up and down by means of a cross small link installed in space between a nut screwed in a screw shaft and an X-form cross link. CONSTITUTION:Each of respective ends of two cross small links 20 is pivoted (22 and 23) to a block 19 of a nut 18 and two X-form links 4 and 4 and these links 20 are interposed between these elements. Likewise, each of respective ends of two cross small links 24 is pivoted (23 and 26) to two X-form cross links 4 and 4 and a block 16 of a driving mechanism 10, and these links 24 are interposed between these elements. If an electric motor of this driving mechanism 10 is rotated clockwise, a screw shaft 17 is also rotated clockwise and shifts so as to make the nut 18 come nearer to the driving mechanism 10. With this movement, both these cross small links 20 and 24 are expanded wide, thereby expanding another X-form cross link 3 wide and making a ramp 2 go upward. With movements of the nut 18 rotating a motor 11 in reverse, this X-form cross link 3 is closed and the ramp 2 is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric table lifter in which an X-shaped cross link is provided between a fixed base and a lift table, and the lift table is vertically moved by opening and closing the cross link.

[0002]

2. Description of the Related Art An X-shaped cross link is provided between a fixed base and a lift, a pair of bulging arc-shaped guides are provided on the inner surfaces of the cross link facing each other, and the guides rotate in contact with the respective guide surfaces. An electric table lifter in which a wedge roller is interposed and an electric linear actuation mechanism is connected to the wedge roller is known (see Japanese Utility Model Laid-Open No. 2-40793).

[0003]

In the above-mentioned known electric table lifter, a rotary roller is interposed between a pair of bulging arc-shaped guides on the inner surface of the X-shaped cross link facing each other, and the rotary roller is expanded with respect to the pair of cross links. As a result of the opening and closing operation of the cross link by the opening action, there is a problem that the cross link and the rotating roller must be made of a steel material having high abrasion resistance, and that a mechanism with high dimensional accuracy must be used. The present invention provides a novel electric table lifter having a very simple mechanism.

[0004]

In order to solve the above-mentioned problems, the present invention pivotally mounts the central crossing portions of a pair of X-shaped cross links, and connects one end of the X-shaped cross links to a fixed base and a lift. Each of them is pivotally connected to each other, and a rolling roller is provided at the opposite free end to contact the fixed base and the lifting platform, and the screw shaft is attached to the connecting portion of the drive mechanism including the electric motor, the speed reducer and the drive shaft having the connecting portion. It is characterized in that they are connected and a nut is screwed onto this screw shaft, and small cross links are respectively interposed between the nut and the X-shaped cross link and between the X-shaped cross link and the drive mechanism.

[0005]

In the electric table lifter of the present invention, the screw shaft rotates forward and backward by rotating the drive motor of the drive mechanism forward and backward, and the nut screwed to the screw shaft is moved forward and backward. As the nut moves forward and backward, small cross links between the nut and the X-shaped cross link and between the X-shaped cross link and the drive mechanism are opened and closed to raise and lower the lift table on the fixed base. Operate.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below. A basic embodiment is shown in FIGS. 1 to 4, in which 1 is a fixed base, 2 is a lifting platform, 3 is an X-shaped cross link, and a central portion of a pair of link members 4 and 4 is a pivot shaft 5. It is connected so that it can be opened and closed. The X-shaped cross links 3 are arranged in front and rear as a pair as shown in the plan view of FIG. One end of each link member 4 of these X-shaped cross links 3 is pivotally attached 6, 7 to the fixed base 1 and the lift 2. On the other hand, these X-shaped cross links 3
At the opposite free end of each link member 4 of
Is provided so as to be brought into contact with the inner surfaces of the base 1 and the lifting table 2 to roll.

In the figure, 10 is a drive mechanism, and this drive mechanism
A drive shaft 13 having an electric motor 11, a reduction mechanism 12 and a connecting portion 14, and a cover case 1 for covering the connecting portion 14.
5 and a block 16 fixed to this cover case. A screw shaft 17 is connected to the connecting portion 14 of the drive shaft 13 of the drive mechanism 10.
A nut 18, which is integrally provided with a block 19, is screwed into the screw 7.

Further, in the drawing, 20 is a link member 21, 21.
The crossing small link 20 is formed by crossing each other, and the crossing small link 20 has the respective ends of the crossing small link 20 and the block 19 of the nut 18 and the X
Pivot links 22 and 23 are attached to the cross links 4 and 4 and are interposed therebetween. Similarly, in the figure, 24 is the link members 25 and 2.
5 are crossed small links, and these small cross links 25 are pivotally attached at their ends to the X-shaped cross links 4 and 4 and the block 16 of the drive mechanism 10 between them. Intervened in. And these crossover small link 2
0 and 24 drive mechanism 10 and screw shaft 17
Is arranged between the base 1 and the lifting table 2, and the drive mechanism 10 is not fixed to the X-shaped cross link 3 but is in a floating state.

In addition, reference numeral 27 in the figure is a safety mechanism, which is composed of a detection plate 28 provided on the lift table so as to be vertically displaceable, and a detection switch 29 provided on the detection plate 28. When the button is pushed up, the detection is detected by the detection switch to stop the operation of the electric motor 11, and the safety is ensured so that a person is not caught between the base 1 and the lift 2.

FIG. 2 shows a state in which the lift 2 is lowered. When the electric motor of the drive mechanism 10 is normally rotated in this state, the screw shaft 17 is rotated in the normal direction to move the nut 18 from the position in FIG. 2 to the right, that is, toward the drive mechanism 10. By the movement of the nut 18, the small cross links 20 and 24 are expanded, the X-shaped cross link 3 is expanded, and the lift 2 is raised. Similarly, when the electric motor 11 is rotated in the reverse direction, the nut 18 moves from the position in FIG. 1 to the left in the figure, and the closing operation of the small cross links 20 and 24 causes X.
The cross link 3 is closed, and the lift table 2 is lowered from the state of FIG. 1 to the state of FIG.

FIG. 5 shows a preferred embodiment in which guide rods 30 and 30 are further provided in the embodiment shown in FIGS. 1 to 4, and the same reference numerals as those shown in FIGS. 1 to 4 are shown. The members are the same member. This guide rod 30,30
Is fixed to the block 16 of the drive mechanism 10, a through hole is formed in the block 19 of the nut 18, and the through hole is penetrated. As a result, stable operation of each member can be obtained.

6 and 7, two screw shafts 1 are shown.
Another embodiment in which 7, 17 are provided is shown. Therefore, a gear system 31 is interposed between the drive mechanism 10 and the drive shaft. Also in this embodiment, the members denoted by the same reference numerals as those shown in FIGS. 1 to 4 are the same members. Further, in this embodiment as well, by providing the screw shafts 17 and 17, more stable operation can be obtained.

FIGS. 8 to 10 show an embodiment in which the drive mechanism 10 is fixed to the pivot 5 of the X-shaped cross link 3 without floating. That is, the drive mechanism 10 is fixed to the X-shaped cross link 3 by the fixing rods 32, 32.
The members denoted by the same reference numerals as those shown in FIG. 4 are the same members.

Further, FIG. 11 shows the guide rods 30, 3 similar to the embodiment shown in FIG. 5 in the embodiment shown in FIGS.
An example in which 0 is provided is shown.

Further, FIG. 12 is a block 16 of the X-shaped cross link 3 and the drive mechanism 10 of the embodiment shown in FIGS.
An example is shown in which the small cross link 24 interposed between the two is omitted, and the members designated by the same reference numerals as those in FIGS. 1 to 4 are the same members. Each of these embodiments operates in the same manner as the embodiment shown in FIGS.

[0015]

According to the electric table lifter of the present invention, X
A drive mechanism for opening and closing the cross link, a screw shaft connected to the drive mechanism, and a nut screwed to the screw shaft,
Since the raising and lowering operation of the lifting platform is configured by the small cross links provided between the nut and the X-shaped cross link and / or between the X-shaped cross link and the drive mechanism, it is possible to form a very simple mechanism. The operation is safe and reliable, and the maintenance is easy.

[Brief description of drawings]

FIG. 1 is a front view showing a lifted state of a preferred embodiment of an electric table lifter according to the present invention.

FIG. 2 is a front view of the same descending state.

[FIG. 3] Similarly, a half-section side view

FIG. 4 is a partial cross-sectional plan view showing the lift base also omitted.

FIG. 5 is a partial cross-sectional plan view similar to FIG. 4 showing another embodiment.

FIG. 6 is a partial cross-sectional plan view similar to FIG. 4 of the embodiment in which two screw shafts are provided.

FIG. 7 is a half sectional side view of the embodiment of FIG.

FIG. 8 is a front view showing a lifted state of yet another embodiment in which a drive mechanism is fixed to an X-shaped cross link.

9 is a front view of the embodiment shown in FIG. 8 in a lowered state.

FIG. 10 is a partially sectional plan view of the embodiment shown in FIG.

11 is a plan view similar to FIG. 10 of an embodiment in which a guide rod is provided in the embodiment of FIGS.

FIG. 12 is a front view similar to FIG. 8 with one small cross link omitted.

[Explanation of symbols]

 1 Fixed Base 2 Lifting Table 3 X-Shaped Cross Link 4 Link Member 5 Axis 6,7 Pivot 8,9 Rolling Roller 10 Drive Mechanism 11 Electric Motor 12 Reducer 13 Drive Axis 14 Connection 15 Cover Case 16 Block 17 Screw Shaft 18 Nut 19 Block 20 Crossing small link 21 Link member 22,23 Pivoting 24 Crossing small link 25 Link member 26 Pivoting 27 Safety mechanism 28 Detecting plate 29 Detecting switch 30 Guide rod 31 Gear system

Claims (5)

[Claims] 1. A pair of X-shaped cross links are pivotally attached to a central crossing portion, one ends of the X-shaped cross links are pivotally attached to a fixed base and an elevator, respectively, and rolling rollers are provided at opposite free ends. The screw shaft is connected to the connecting portion of the drive mechanism including the electric motor, the speed reducer, and the drive shaft having the connecting portion, which is in contact with the fixed base and the elevating table, and the nut is screwed to the screw shaft, An electric table lifter characterized by interposing small cross links between the X-shaped cross links and between the X-shaped cross links and the drive mechanism. 2. The electric table lifter according to claim 1, wherein the drive mechanism is fixed to a pair of X-shaped cross links. 3. The electric table lifter according to claim 2, wherein the small cross link between the X-shaped cross link and the drive mechanism is omitted. 4. The electric table lifter according to claim 1, wherein the number of screw shafts is two. 5. The electric table lifter according to claim 1, wherein a guide rod is provided between the drive mechanism and the nut.