JPH0451632Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lifting device suitably used for furniture such as chairs and tables. [Prior Art] Many furniture such as study desks are equipped with a lifting device for raising and lowering a top plate. A typical example of such a lifting device includes a pair of extendable and retractable vertical frames forming a support, a horizontal frame installed between these vertical frames, and an input end located at the end of the horizontal frame. a screw-type elevating position adjustment mechanism provided in the vertical frame and converting rotational movement applied to the input end of the vertical frame into a telescopic movement of the vertical frame; and a screw type elevating position adjustment mechanism provided in the horizontal frame at the input end of the elevating position adjusting mechanism. A device is known that is equipped with a transmission mechanism that transmits a rotational operating force applied to an operating handle, and configured so that the top plate portion can be raised and lowered by expanding and contracting the vertical frame. In order for such devices to operate reliably and quietly with a simple structure,
A crank type transmission mechanism is widely used as the transmission mechanism. In addition, the conventional crank type transmission mechanism includes a driven crank attached to the input end of the vertical position adjustment mechanism, a driving crank provided on the operating handle corresponding to the driven crank, and a rotational force of the driving crank. It is equipped with a crank lever that transmits transmission to the crank.

Recently, this type of lifting and lowering installation has been
Application to the lifting and lowering of movable parts of other furniture, such as chair seats and table tops, is also being considered.

[Problems to be solved by the invention] By the way, in furniture such as chairs and tables, where the raising and lowering position can be adjusted without applying a large load to the movable parts, it is difficult to adjust the vertical position per rotation of the operating handle. It is important to set the amount of change in the vertical position of the movable part to be relatively large in order to improve operability.

However, in the above-mentioned crank type lifting device, it is not possible to increase the speed of the transmission mechanism, so in order to increase the amount of change in the lifting position of the movable part per rotation of the operating handle, it is necessary to use a lifting position adjustment mechanism. It is necessary to increase the lead by making the thread part a multi-thread thread. However, this reduces the self-locking function of the threaded part, so if a large load is applied to the movable part, such as when a person sits on the seat of a chair or a heavy item is placed on the table top. When placed on the table, the seat or top plate tends to fall unduly due to the load. One possible solution to this problem is to provide a stopper mechanism to lock the movable part at an appropriate position, but adding a special stopper mechanism increases the number of parts and complicates the structure. This not only leads to the problem of complication, but also makes the operation complicated.

Further, in the conventional crank mechanism type, the driven crank is directly connected to the input end as described above. However, since the driven crank normally performs a non-directional thrusting and retracting operation when activated,
It is unavoidable that the rotation locus becomes bulky compared to the effective diameter. Therefore, the end of the horizontal frame must be placed in a position that protrudes outward from the outer surface of the vertical frame until the most protruding crank can be accommodated, which is an inconvenience that increases the number of design restrictions. There is.

Furthermore, if the entire transmission mechanism is integrally restrained and chained by such a crank mechanism, there are no elemental parts on the crank mechanism that can be easily attached and detached, and assembly errors may cause damage to the seat or top. There is a problem in that it is difficult to adjust the height between the left and right elevating position adjustment mechanisms when the horizontality of the plate becomes inconsistent.

The present invention aims to reliably solve these problems with a simple configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention uses a lifting device of the type described above, in which the transmission mechanism is a small-diameter gear attached to the input end of the lifting position adjustment mechanism. , a large-diameter gear positioned inward from the small-diameter gear and supported by the horizontal frame and meshing with the small-diameter gear, a driven crank attached to the large-diameter gear, and a driven crank provided on the operating handle in correspondence with the driven crank. The present invention is characterized in that it is equipped with a driving crank and a crank lever that transmits the rotational force of the driving crank to a driven crank.

[Function] With this configuration, when the operating handle provided on the horizontal frame is rotated, the rotational operating force is transmitted from the driving crank to the driven crank via the crank lever, and the large-diameter gear rotates. .
Then, the small diameter gear meshed with the large diameter gear is rotationally driven together with the input end of the elevation position adjustment mechanism. As a result, the vertical frame expands and contracts by a height corresponding to the amount of rotation of the input end, and the movable part of the furniture such as a chair moves up and down accordingly. In this case, the driven crank rotates at the same speed as the driving crank, but the rotation of the driven crank is accelerated by the cooperation of the large diameter gear and the small diameter gear and is transmitted to the input end of the elevation position adjustment mechanism. Ru. Therefore, the amount of change in the vertical position of the movable part per one rotation of the operating handle can be set to be larger than in the conventional case.

Furthermore, this device has gears with a smaller rotational trajectory than the effective diameter attached to the input ends of the vertical position adjustment mechanism located at both ends of the horizontal frame, and the gears are small in diameter. Since the large-diameter gear and the driven crank that mesh with the large-diameter gear are arranged inwardly, the input end portion does not become bulkier than the outer diameter of the small-diameter gear. Therefore, it becomes possible to adopt an unprecedented mode such as aligning the end surface of the horizontal frame and the outer surface of the vertical frame substantially flush and assembling the frame for a good appearance, thereby increasing the degree of freedom in design.

Furthermore, this gear releases the meshing state by displacing the small diameter gear and the large diameter gear relative to each other in the axial direction.
The restraint chain between the left and right vertical position adjustment mechanisms can be temporarily released, and the small-diameter gear or the large-diameter gear can be made independently rotatable. Therefore, by slightly rotating one of the gears and re-engaging it, you can set the linkage point between the left and right lifting position adjustment mechanisms to a different position than before, and the levelness of the seat or top plate will be distorted. It becomes possible to easily make corrections when this occurs.

[Example] Hereinafter, an example in which the present invention is applied to a chair will be described with reference to FIGS. 1 to 4.

The chair 1 shown in FIG. 1 is provided with a movable part 5 consisting of a seat 3 and a backrest 4 on leg parts 2 so as to be movable up and down. A lifting device 6 is provided.

As shown in FIG. 2, the elevating device 6 includes a pair of extendable vertical frames 7 that constitute the support portions of the leg portions 2, a horizontal frame 8 installed between these vertical frames 7, and this horizontal frame. a screw-type elevating position adjustment mechanism 11 that is provided in each of the vertical frames 7 with an input end 9 located at the end of the vertical frame 8 and converts rotational movement applied to the input end 9 into an expansion/contraction movement of the vertical frame 7; , an operation handle 1 provided on the horizontal frame 8 at the input end 9 of this elevating position adjustment mechanism 11.
Transmission mechanism 1 that transmits the rotational operating force applied to 2
3.

The vertical frame 7 includes a leg cover 15 erected on the base member 14 of the leg part 2, and a movable column 16 whose upper end projects outward and is fitted into the leg cover 15 so as to be vertically slidable. , and a fixed column 17 located inside the movable column 16 and erected on the base member 14.
The end of the horizontal frame 8 is fixed to the upper end of the horizontal frame 8.

The horizontal frame 8 is shaped like a rectangular pipe, and its end surface 8a is aligned with the outer surface 16a of the movable column 16, and the seat 3 is fixed onto the horizontal frame 8. In this embodiment, the outer surface 18a of the side plate 18 of the seat 3 is connected to the end surface 8 of the horizontal frame 8.
It almost matches a. The input end 9 of the elevating position adjustment mechanism 11 is made to protrude near the end face of the horizontal frame 8.

The elevating position adjustment mechanism 11 is of a screw type, comprising a nut 21 fixed to the upper end of the fixed column 17, and a bolt 22 screwed into the nut 21, for example, using a trapezoidal single thread screw. ing.
A small diameter shaft portion 23 is provided at the upper end of the bolt 22, and this small diameter shaft portion 23 is passed through the bottom plate 8b of the horizontal frame 8 to form the input end 9. The transmission mechanism 1 is connected to this input end 9.
By fixing the small diameter gear 24 of No. 3 and interposing a thrust bearing 25 between the end face 22a of the bolt 22 and the bottom plate 8b of the horizontal frame 8, this bolt 22 can be attached to the horizontal frame 8 in the forward and reverse directions. It is held rotatably.

The transmission mechanism 13 includes the aforementioned small-diameter gear 24 and a large-diameter gear 27 positioned inwardly from the small-diameter gear 24 and supported by the horizontal frame 8 via a support shaft 26 and meshed with the small-diameter gear 24. , a driven crank 28 attached to this large-diameter gear 27, and the operating handle 12 corresponding to this driven crank 28.
The drive crank 29 is provided with a drive crank 29, and a crank lever 31 that transmits the rotational force of the drive crank 29 to the driven crank 28. The driven crank 28 has a crank pin 32 erected at a required eccentric position of the large-diameter gear 27, and one end of the crank lever 31 is rotatably engaged with the crank pin 32. drive crank 29
A crank pin 34 is provided upright on a crank arm 33 fixed to the rotating shaft 12a of the operating handle 12, and the other end of the crank lever 31 is rotatably engaged with the crank pin 34. The crank lever 31 is a long flat plate.
A slit 35 is provided in the center, and a guide pin 36 fixed to the horizontal frame 8 is passed through the slit 35.

If the configuration is like this, the horizontal frame 8
When the operating handle 12 provided in the main body is rotated, the rotational operating force is transmitted from the driving crank 29 to the driven crank 28 via the crank lever 31, and the large diameter gear 27 is rotated. And this large diameter gear 27
The small diameter gear 24 meshed with is rotationally driven,
Along with this small diameter gear 24, the lifting position adjustment mechanism 11
The input end 9 of rotates. As a result, the horizontal frame 8
A bolt 22 held by the bolt 22 moves forward and backward into engagement with a nut 21 fixed to the fixed support 17. As a result, the movable struts 16 of the vertical frame 7 slide against the fixed struts 17 and the leg covers 15, the vertical frame 7 expands and contracts, and the horizontal frame 8 moves up and down. Therefore, the seat 3 and the backrest 4 held by the horizontal frame 8 are connected to the operating handle 12.
It will rise or fall by the height corresponding to the rotational operation input applied to it. In this case, the large-diameter gear 27 rotates at the same angular velocity as the operating handle 12 due to the characteristics of the crank system, but the small-diameter gear 24 rotates at a higher angular velocity than the large-diameter gear 27. Therefore, the amount of rotation of the bolt 22 per rotation of the operating handle can be made larger than in the conventional case. In other words, in the conventional device, the input end of the vertical position adjustment mechanism is directly connected to the driven crank, so the relative rotational angular velocity between the bolt and nut is equal to the angular velocity of the operating handle, but in the device of the present invention, , the bolt 22
The relative angular velocity between the nut 21 and the operating handle 12 can be made higher than the angular velocity of the operating handle 12. Therefore, it is possible to increase the amount of change in the vertical position of the seat 3 per one rotation of the operating handle compared to the conventional one, without increasing the lead by using a multithread thread. Therefore, the elevating position adjustment mechanism 1
without reducing the self-lock function of 1.
It is possible to speed up the lifting and lowering position adjustment work, and it is possible to ensure good operability.

Furthermore, this device is based on a transmission system using cranks 28 and 29, and has a pair of gears 2.
4 and 27, there are disadvantages when adopting a transmission method using a chain, such as a significant increase in the number of parts, and a large sliding noise during operation due to contact between the chain and the horizontal frame. This enables quiet and reliable operation without causing inconveniences such as.

In addition, if the driven crank is directly attached to the input end of the elevating position adjustment mechanism as in the conventional case,
Due to the bulk of this driven crank, it becomes necessary to make the end of the horizontal frame protrude outward from the outer surface of the vertical frame, which is disadvantageous in that it is easily subject to design constraints.However, the device of the present invention Such problems can be solved. That is, in the case of a crank-type transmission mechanism, reducing the crank diameter generally impairs smooth operation.
Therefore, it is difficult to make the driven crank itself low in bulk. As shown in FIGS. 3a and 3b, even if the effective diameter d ₁ of the driven crank 101 can be made equal to the effective diameter d of the small diameter gear 24 of this device, the crank pin 102 is loaded with In addition, the crank pin 102 must be held by the crank arm 103, so the outer diameter _D1 of the driven crank 101 is considerably larger than the outer diameter D of the small diameter gear 24. I have no choice but to do so. Therefore, in the conventional type in which the driven crank 101 is directly connected to the input end, due to the bulk of the driven crank 101, it is necessary to make the end of the horizontal frame protrude outward from the outer surface of the vertical frame. , the number of design restrictions increases accordingly. In contrast, in the device of the present invention, the driven crank 28 is arranged inside the input end 9, and the small diameter gear 24 is attached to the input end 9, so that the bulkiness of the input end 9 portion is eliminated. This can increase the degree of freedom in design. Specifically, as in this embodiment, the end surface 8a of the horizontal frame 8 and the outer surface of the vertical frame 7 are set to be substantially flush with each other, and the outer surface 18a of the side plate 18 of the seat 3 is
It is also possible to easily adopt a form in which the outer surface of the leg portion 2 and the outer surface of the leg portion 2 are made to substantially coincide with each other.

Furthermore, this thing has a small diameter gear 24 and a large diameter gear 2.
7 in the axial direction to release the meshing state, the restraint chain between the left and right lifting position adjustment mechanisms 11, 11 is temporarily released, and the small diameter gear 24 or the large diameter gear 27 can be rotated independently. You can get used to it. Therefore, by slightly rotating either of the gears 24, 27 and engaging them again, the linkage point between the left and right lifting position adjustment mechanisms 11, 11 can be changed to a different position than before, and the seat 3 and It becomes possible to easily perform correction when a deviation occurs in levelness.

Note that the present invention can also be implemented in the following manner.

First, as shown in FIG. 4, a horizontal frame 201 may be provided between the lower ends of vertical frames 202. That is, in this case, a horizontal frame 201 having an operating handle 203 is attached to a base member 20 of a leg portion 204.
5, and the seat 206 is supported by the upper end of the vertical frame 202 which is connected to the upper surface of both ends of the horizontal frame 201. In this embodiment, the vertical frame 202 is replaced by the horizontal frame 2.
A fixed column 207 fixed to 01 and a movable column 2 slidably fitted inside this fixed column 207.
It consists of 08. In this way, a nut (not shown) is directly fixed to the movable column 208, and a bolt (not shown) supported by the horizontal frame 201 is screwed into this nut to adjust the vertical position. Since the mechanism can be configured, the structure can be further simplified.

Further, in the above embodiments, the case where the present invention is applied to a chair has been described, but the present invention can be similarly applied to tables and other furniture. For example, when applied to a table, the top plate may be supported by the ends of the vertical frame or the horizontal frame, and the top plate may be raised and lowered by the expansion and contraction of the vertical frame.

[Effects of the invention] Since the present invention has the above-described configuration, the following effects can be obtained.

First, since the rotational operation input applied to the operating handle is accelerated by the transmission mechanism and transmitted to the input end of the elevation position adjustment mechanism, the self-locking function of the elevation position adjustment mechanism may be unduly degraded. It is possible to increase the amount of change in the vertical position of the movable part per one rotation of the operating handle. Therefore, it is possible to speed up the operation and improve operability.

Moreover, since the transmission mechanism is based on a crank system, it is relatively easy to reduce the weight.
In addition, unlike the case where a speed increase function is provided by adopting a chain system, etc., the number of parts can be kept to a minimum and quiet operation without emitting sliding noise etc. can be expected. You can get the effect that you can.

Furthermore, a small diameter gear is attached to the input end of the elevating position adjustment mechanism located at the end of the horizontal frame, and a bulky driven crank is placed inside it, so that the end of the horizontal frame is connected to the vertical frame. The conventional constraint of having to protrude outward beyond the outer surface is eliminated. Therefore, it becomes possible to effectively increase the degree of freedom in design, and it is also possible to obtain the effect that the invention can be applied more widely and more easily to various forms of furniture.

Furthermore, by releasing the meshing state between the small-diameter gear and the large-diameter gear, the restraint chain between the left and right lifting position adjustment mechanisms is temporarily released, allowing the small-diameter gear or the large-diameter gear to rotate independently. It can be done. Therefore, by slightly rotating one of the gears and re-engaging it, you can set the linkage point between the left and right lifting position adjustment mechanisms to a different position than before, and the levelness of the seat or top plate will be distorted. This makes it possible to easily make corrections when this occurs.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention; Figure 1 is an overall perspective view, Figure 2 is a partial sectional view showing the main parts, and Figures 3a and 3b are for explaining the effects. FIG. FIG. 4 is a perspective view showing another embodiment. 1...Chair, 3...Seat, 4...Backrest, 5...
...Movable part, 6... Lifting device, 7... Vertical frame,
8...Horizontal frame, 9...Input end, 11...Elevating position adjustment mechanism, 12...Operation handle, 13...
Transmission mechanism, 24... Small diameter gear, 27... Large diameter gear, 28... Driven crank, 29... Drive crank, 31... Crank lever, 201... Horizontal frame, 202... Vertical frame, 203... Operation Handle, 206... seat.

Claims (1)

[Claim for Utility Model Registration] A pair of extendable and retractable vertical frames constituting the supports of furniture such as chairs, a horizontal frame provided between these vertical frames, and an input end located at the end of the horizontal frame. a screw-type elevating position adjustment mechanism provided in the vertical frame and converting rotational movement applied to the input end thereof into an extending/contracting movement of the vertical frame; and an operation provided on the horizontal frame at the input end of the elevating position adjusting mechanism. A lifting device comprising a transmission mechanism that transmits a rotational operation force applied to a handle, and configured to raise and lower a movable part of furniture such as a chair by expanding and contracting the vertical frame, the transmission mechanism comprising: a small-diameter gear attached to the input end of the vertical position adjustment mechanism; a large-diameter gear located inwardly of the small-diameter gear and supported by the horizontal frame and meshed with the small-diameter gear; and a large-diameter gear attached to the large-diameter gear. A chair comprising a driven crank, a driving crank provided on the operating handle in correspondence with the driven crank, and a crank lever that transmits the rotational force of the driving crank to the driven crank. etc. Furniture lifting device.