Lift table

Abstract

To provide a table in which failures are eliminated, failures such that variance occurs in the movement of a ratchet device inside lateral leg bodies in raising / lowering a top plate, or that hinderance is likely to occur in light movement and stacking in the event of installing a highly rigid horizontal member near the floor surface for the purpose of connecting to eliminate posture changes of the lower leg elements in the lateral leg bodies for the floor surface.SOLUTION: Where the leg bodies 2 support both lateral end parts 1a, 1b of the top plate 1 respectively, the leg bodies 2 are equipped with an upper leg element 21 and lower leg element 22 for relative vertical operations respectively. In these leg bodies 2, there are assembled in the lifting table T a manual ratchet device by which a plurality of height positions can be sequentially locked by raising the top plate 1. In the structure of this table, the lateral leg bodies 2 are rigidly connected to each other by only the upper leg element 21, while the lower leg element 22 can be made individually inclined respectively for the floor surface F without being rigidly connected.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to a lift-up table whose top plate can be raised and lowered. [Background technology]

[0002] 2. Description of the Related Art Recently, in offices and the like, various types of lift-up tables have been developed that allow the height position of the tabletop to be appropriately adjusted in order to accommodate diversifying work styles.

[0003] This type of lift table has left and right ends of the tabletop supported by legs that can expand and contract vertically, and both legs can be extended and contracted simultaneously by an electric actuator or the like contained within each leg, allowing the tabletop to be raised and lowered while keeping it horizontal.

[0004] The legs of such a lift table include a lower leg element supported on the floor surface and an upper leg element that can be raised and lowered relative to the lower leg element, and the upper leg elements of the left and right legs are connected to the left and right ends of the tabletop, respectively. The lower leg elements of both legs are rigidly connected to each other so as to always maintain a constant upright posture relative to the floor surface, and the movements of the electric actuators in both legs are highly synchronized to raise and lower the tabletop (see, for example, Patent Document 1).

[0005] Recently, there has been a demand for tables that can be easily moved and stacked, but it is difficult to meet this demand using conventional methods.

[0006] That is, in order to realize the lifting and lowering of the tabletop in a table that can be used easily, for example, it is conceivable to incorporate a manual ratchet device in place of an electric actuator in the left and right legs. However, it is extremely difficult for two people to lift both the left and right ends of the tabletop and accurately synchronize the left and right ratchet devices, and if there is a difference in the movement of the left and right ratchet devices, a force will act to tilt the upper leg element relative to the lower leg element, which is expected to hinder the smooth sliding between the upper leg element and the lower leg element. In addition, in order to connect the lower leg elements of the left and right legs so that their posture does not change relative to the floor surface, it is necessary to install a highly rigid horizontal member near the floor surface, which is expected to cause problems such as easy hindrance to easy movement and stacking. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2020-494 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a lift-up table that can easily solve the above-mentioned problems. [Means for solving the problem]

[0009] The lift-up table of the invention described in claim 1 has a tabletop whose left and right ends are supported by legs, each of which is equipped with upper and lower leg elements that move relative to one another in the vertical direction, and each of which is equipped with a manual ratchet device that allows the tabletop to be sequentially locked at multiple height positions by lifting it.The left and right legs are rigidly connected to each other only through the upper leg elements, and the lower leg elements are not rigidly connected and are configured so that they can be tilted individually relative to the floor surface.

[0010] In this specification, the term "lift-up table" refers to any furniture with a lift-up top, including desks and tables in the narrow sense.

[0011] The lift-up table of the invention described in claim 2 is the one described in claim 1, wherein the leg body is formed by telescopically engaging an upper tube and a lower tube, the upper leg element being mainly constituted by the upper tube, and the lower leg element being mainly constituted by the lower tube and a leg base provided at the lower end of the lower tube.

[0012] The lift table according to the invention recited in claim 3 is the lift table recited in claim 2, wherein the upper cylinders of the left and right legs are rigidly connected to each other by a connecting beam.

[0013] The lift-up table of the invention described in claim 4 is the one described in claim 2 or 3, wherein the lower cylinders of the left and right legs are configured so as to be able to tilt left and right together with the leg bases relative to the floor surface.

[0014] The lifting table according to the invention recited in claim 5 is the lifting table recited in claim 2, 3 or 4, and further comprises a rotation prohibiting means for prohibiting the upper tube and the lower tube from rotating relative to each other around their axes. Effect of the Invention

[0015] According to the present invention, a lift-up table can be provided that can ensure smooth operation even when manual ratchet devices are provided on each of the left and right legs, and that can be easily designed to enable easy movement and stacking. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing a lift table according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4]FIG. [Diagram 5] FIG. 4 is an exploded perspective view showing a connection state of both legs of the lift-up table. [Figure 6] FIG. 4 is an enlarged central vertical cross-sectional view of a portion including a ratchet device of the lifting table. [Figure 7] FIG. 7 is a cross-sectional view taken along line AA in FIG. [Figure 8] FIG. 7 is a cross-sectional view taken along line BB in FIG. [Figure 9] FIG. 4 is an enlarged perspective view of a portion including a ratchet device of the lifting table. [Figure 10] FIG. 4 is an enlarged perspective view showing a ratchet device of the lifting table. [Figure 11] FIG. 4 is an exploded perspective view showing a ratchet device of the lifting table. [Figure 12] 5 is an explanatory diagram showing the operation of the ratchet device of the lifting table. FIG. [Figure 13] 5 is an explanatory diagram showing the operation of the ratchet device of the lifting table. FIG. [Figure 14] 5 is an explanatory diagram showing the operation of the ratchet device of the lifting table. FIG. [Figure 15] 5 is an explanatory diagram showing the operation of the ratchet device of the lifting table. FIG. [Figure 16] 5A to 5C are explanatory diagrams showing the procedure for lifting and lowering the tabletop of the lift table. [Figure 17] 5A to 5C are explanatory diagrams showing the procedure for lifting and lowering the tabletop of the lift table. [Figure 18] 5A to 5C are explanatory diagrams showing the procedure for lifting and lowering the tabletop of the lift table. [Figure 19] 5A to 5C are explanatory diagrams showing the procedure for lifting and lowering the tabletop of the lift table. [Figure 20] 5A to 5C are explanatory diagrams showing the procedure for lifting and lowering the tabletop of the lift table. [Figure 21] 5A to 5C are explanatory diagrams showing the procedure for lifting and lowering the tabletop of the lift table. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

[0018] In this embodiment, the present invention is applied to a lift table T having a ratchet device X.

[0019] 1 to 4, the lift-up table T is configured such that both left and right ends 1a, 1b of the tabletop 1 are supported by legs 2, and these legs 2 are equipped with upper leg elements 21 and lower leg elements 22 that move relative to each other in the vertical direction, and each leg 2 is equipped with a manual ratchet device X that can be successively locked at a plurality of height positions by lifting the tabletop 1. Only the upper leg elements 21 of the left and right leg bodies 2 are rigidly connected to each other, and the lower leg elements 22 are not rigidly connected and are configured so that they can be tilted independently with respect to the floor surface F.

[0020] The tabletop 1 has, for example, a rectangular shape in a plan view, and as shown in Figs. 1, 3 and 4, tabletop receivers 12 are fixed to the bottom surface 11 near both left and right ends 1a. The tabletop receiver 12 has a channel shape that opens downward, and is rotatably connected to an axis plate 215 (described later) provided at the upper end of the leg 2 via a tabletop support shaft 13. That is, as shown in Fig. 4, the tabletop 1 can rotate around the tabletop support shaft 13 with respect to the left and right leg 2, and can perform a flap operation between a horizontal use position (see solid line) and a flip-up position (see imaginary line). A tabletop locking mechanism (not shown) related to the flap operation of the tabletop 1 is incorporated in the tabletop receiver 12, but since it is a normal mechanism, its description will be omitted. In this specification, the following description will be given with the tabletop 1 locked in a horizontal use position.

[0021] As shown in Figs. 5 to 8, the leg body 2 is formed by engaging an upper cylinder 211 and a lower cylinder 221 in a telescopic manner. The upper leg element 21 of the leg body 2 is mainly composed of the upper cylinder 211, and the lower leg element 22 is mainly composed of the lower cylinder 221 and a leg base 224 provided at the lower end of the lower cylinder 221, and casters 225 are provided on each leg base 224. The upper cylinders 211 of the left and right leg bodies 2 are rigidly connected to each other by a connecting beam 3. The lower cylinders 221 of the left and right leg bodies 2 are not connected to each other at all, and each lower cylinder 221 is configured to be able to tilt left and right together with the leg base 224 with respect to the floor surface F. As shown in Figures 6 to 8, the upper cylinder 211 is slidably fitted to the lower cylinder 221 with the axis j1 aligned, so that when the lower cylinder 221 tilts with respect to the floor surface F, the upper cylinder 211 also tilts together with the corresponding lower cylinder 221, as shown in Figures 16, 18, and 20. Note that since the left and right upper cylinders 211 are rigidly connected to each other by the connecting beam 3, they always maintain a parallel state in a position perpendicular to the top board 1. Therefore, the left and right lower cylinders 221 held by these upper cylinders 211 so as to be vertically slidable can also tilt by the same angle with respect to the floor surface F while maintaining a mutually parallel position.

[0022] More specifically, as shown in Figures 5 to 8, the upper leg element 21 of the leg body 2 comprises a cylindrical upper tube 211, a cap 212 fitted to the upper end of the upper tube 211, a fixed plate 213 fixed to the inner periphery near the upper end of the upper tube 211, a claw holding member 7 attached to the fixed plate 213 and hanging down inside the upper tube, a plate nut 214 fixed to the outer periphery of the upper end of the upper tube 211 by welding or the like, and an axle plate 215 screwed to this plate nut 214, and the axle plates 215 of the left and right legs 2 are rigidly connected to each other by a connecting beam 3. That is, the axle plate 215 is made of die-cast material and comprises a body 215a which is screwed to the plate nut 214 of the leg body 2 via a bolt G, and a head 215b which is integrally formed at the upper end of the body 215a and supports the tabletop 1 via the tabletop support shaft 13. The body parts 215a of the axle plates 215 on the left and right legs 2 are rigidly connected to each other by the aforementioned connecting beam 3 which has a circular pipe shape.

[0023] 5 to 8, the lower leg element 22 of the leg body 2 includes a cylindrical lower tube 221 slidably fitted to the inner circumference of the upper tube 211, an upper end sleeve 222 provided on the outer circumference of the upper end of the lower tube 221, an intermediate sleeve 223 provided on the outer circumference of the middle part of the lower tube 221, a leg base 224 attached to the lower end of the lower tube 221, and a claw receiving member 8 supported by the upper end sleeve 222 and fixed in the lower tube 221, and the outer circumferences of the upper end sleeve 222 and the intermediate sleeve 223 are slidably fitted to the inner circumference of the upper tube 211. There is no direct connection between the lower leg elements 22 of the left and right legs 2.

[0024] As shown in Fig. 7 to Fig. 9, a rotation prohibition means 23 is provided between the upper cylinder 211 and the lower cylinder 221 of each leg 2 to prohibit the upper cylinder 211 and the lower cylinder 221 from rotating relative to each other around the axis j1. The rotation prohibition means 23 includes a key member 231 parallel to the axis j1 fixed to the inner circumference of the upper cylinder 211 from the upper end to the lower end, and a pair of key groove forming members 232 fixed between the upper end sleeve 222 and the intermediate sleeve 223 on the outer circumference of the lower cylinder 221 so as to slidably hold the key member 231. The upper end sleeve 222 and the intermediate sleeve 223 are each formed with a notch to avoid interference with the key member 231.

[0025] The above-mentioned manual ratchet device X is incorporated in each of the left and right legs 2.

[0026] As shown in Figs. 6, 9 to 11 and 13 to 15, the ratchet device X is configured to be able to sequentially engage the locking pawl 4 with a plurality of pawl engagement portions 5, and the locking pawl 4 is rotatably biased by a single locking spring 6. The rotation range of the locking pawl 4 is divided into a protruding / retracting operating region R1 where the locking pawl 4 can be engaged with and disengaged from the pawl engagement portion 5 and a retracting region R2 where the locking pawl 4 cannot engage with the pawl engagement portion 5, as shown in Fig. 12, with a rotation position Q0 as a consideration point as the boundary. The locking spring 6 is arranged so as to rotatably bias the locking pawl 4 in the protruding direction in the protruding / retracting operating region R1, and to rotatably bias the locking pawl 4 in the retracting direction in the retracting region R2.

[0027] More specifically, as shown in Figs. 6, 9 to 11 and 13 to 15, each ratchet device X includes the aforementioned pawl holding member (first member) 7 that rotatably supports the locking pawl 4, and the aforementioned pawl receiving member (second member) 8 that has a plurality of pawl engagement portions 5. Both members 7, 8 are configured to perform a forward relative movement (movement in which the leg body 2 extends) from a relative position that serves as a starting point (bottom dead center D) to a relative position that serves as an end point (top dead center U) while sequentially engaging the locking pawl 4 in the protruding / retracting operating region R1 with the pawl engagement portions 5, and a reverse relative movement (movement in which the leg body contracts) from the relative position that serves as the end point (top dead center U) to the relative position that serves as the starting point (bottom dead center D) with the locking pawl 4 retracted to the retraction region R2. The locking claw 4 is provided with a claw retraction element (lower protrusion 82 and upper protrusion 83 described later) that utilizes the relative movement of the two members 7, 8 in the forward direction to guide the locking claw 4 from the protruding / retracting operating region R1 to the retraction region R2 before the relative movement of the two members 7, 8 in the forward direction reaches its end point (before the upper cylinder 211 reaches the top dead point U), and a claw return element (inclined protrusion 84 described later) that utilizes the relative movement to guide the locking claw 4 from the retraction region R2 to the protruding / retracting operating region R1 before the relative movement of the two members 7, 8 in the reverse direction returns to the relative position which is the starting point (before the upper cylinder 211 returns to the bottom dead point D).

[0028] As shown in Figures 8 and 10 to 12, the locking claw 4 includes a tip portion 41 that engages with and disengages from the claw engagement portion 5, a base end portion 42 having a pressure-receiving portion 43 that receives a biasing force Z from the tip portion 62 of the locking spring 6, and a bearing portion 44 that is disposed closer to the tip portion 41 than the pressure-receiving portion 43 and forms a rotation center P with respect to the claw holding member 7, which is the first member.

[0029] 11 and 12, the lock spring 6 has a base end 61 supported by the pawl holding member 7 as the first member and a tip 62 connected to the pressure-receiving portion 43 of the lock pawl 4, and the rotation position where the base end 61 of the lock spring 6, the tip 62 of the lock spring, and the rotation center P of the lock pawl 4 are aligned is set as a rotation position Q0 that serves as a consideration point. The lock spring 6 is a torsion coil spring in which the tip end 62 and the base end 61 are elastically biased in directions away from each other by an elastic repulsive force N stored in the middle coil portion 63, and the coil portion 63 is released so as to be able to move freely.

[0030] Specifically, as shown in Figs. 9 to 11, the claw holding member 7, which is the first member, is a channel-shaped member having a back wall 71 extending parallel to the claw receiving member 8, which is the second member, and side walls 72 extending from both side edges of the back wall 71 toward the claw receiving member 8, and is vertically installed within the upper tube 211 with an upper end flange portion 73 provided at the upper end fixed to a fixed plate 213 of the upper tube 211. A shaft mounting hole k for mounting a shaft pin 47 that rotatably supports the lock claw 4 is drilled in both side walls 72 of the claw holding member 7 with the axis jc coinciding therewith. A lower end flange portion 74 that functions as a damper holder is provided at the lower end of the claw holding member 7, and a pair of dampers 75 are held by the lower end flange portion 74. The damper 75 comprises a damper body 76 whose lower end is held by a lower end flange portion 74 and whose upper end is engaged with a locking projection 78 cut and raised from the side wall 72 of the claw holding member 7, and a lifting rod 77 suspended so as to be able to project and retract from the lower end of the damper body 76. Note that the damper body 76 is omitted in Figures 6, 9, 14, and 15. Also, Figure 9 shows only one of the pair of lifting rods 77.

[0031] As shown in Figs. 9 to 11, the claw receiving member 8, which is the second member, is flat and has a plurality of claw engagement parts 5 drilled therein at intervals in the vertical direction. Each claw engagement part 5 is a through hole having a trapezoidal opening shape with a lower piece 51 wider than an upper side 52. The lock claw 4 enters the claw engagement part 5 and its downward surface 4a abuts against the lower side 51 of the claw engagement part 5, thereby entering a locked state (a state in which the top board 1 cannot be lowered), and the lock claw 4 moves upward while sliding its front surface 4b against the upper side 52 of the claw engagement part 5, causing the lock claw 4 to disengage from the claw engagement part 5 and move toward the next claw engagement part 5. In this embodiment, the lowest claw engagement portion 5 is for locking the top plate 1 at a height of 720 mm (lowest position H720), the middle claw engagement portion 5 is for locking the top plate at a height of 800 mm (middle position H800), and the upper claw engagement portion 5 is for locking the top plate at a height of 900 mm (upper position H900). The number and height positions of the claw engagement portions 5 may be set appropriately as required. A damper engagement plate 85 for engaging the tip 77a of the protruding and retracting rod 77 of the damper 75 is provided at the lower end of the claw receiving member 8, so as to cushion the impact when the upper cylinder 211 descends and arrives at the lower starting point D.

[0032] As shown in FIG. 11, the locking claw 4 has a rearward surface 4c of the base end 42 facing the back wall 71 of the claw holding member 7, and a rear projection 45 projecting rearward in the middle portion. The locking claw 4 is rotatably mounted between the side walls 72 of the claw support member 7 by inserting an axle pin 47, which is mounted in an axle mounting hole k provided in the side walls 72 of the claw holding member 7, into the bearing portion 44. A window m is formed in a portion of the back wall 71 of the claw holding member 7 corresponding to the locking claw 4, and the locking claw 4 is held so as to be rotatable between a most protruding position Q1 where the rearward surface 4c of the base end 42 abuts against the back wall 71 of the claw holding member 7, and a retracted position Q2 where the rear projection 45 abuts against the upper edge of the window m. The pressure receiving portion 43 is formed by partially recessing the upper surface of the base end 42 of the locking claw 4. A front projection 46 is protruded from the front side of the base end 41 of the locking claw 4. The forward surface 4b and the downward surface 4a of the locking claw 4 form an acute angle, and the intersection thereof forms a tip portion 41 of the locking claw 4.

[0033] As shown in Fig. 12, the lock spring 6 is disposed above the lock pawl 4 with its base end 61 pivoted to both side walls 71 of the pawl holding member 7, and its tip 62 engages with the pressure-receiving portion 43 of the lock pawl 4. The lock spring 6 is open so that the coil portion 63 can move freely without being constrained, and therefore generates an elastic repulsive force Z along a line of action N connecting the base end 61 and the tip 62 in a side view, and the base end 61 is pivotally supported to both side walls 72 of the pawl holding member 7. In this ratchet device X, the lock spring 6 is disposed in such a manner that the line of action N, which indicates the direction of the elastic repulsive force of the lock spring 6, faces the rotation center P of the lock pawl 4 at a specific rotation position between the most protruding position Q1 and the retracted position Q2 of the lock pawl 4, and this specific rotation position is referred to as the "rotation position Q0 serving as a consideration point" in this specification. That is, Fig. 12(b) shows a state in which the lock claw 4 is in the specific rotation position described above, that is, the rotation position Q0 which is the consideration point. As described above, in the rotation position Q0 which is the consideration point, the base end 61 of the lock spring 6, the tip end 62 of the lock spring 6, and the rotation center P of the lock claw 4 are aligned in a straight line. In other words, the line of action N indicating the direction of the elastic repulsive force Z of the lock spring 6 coincides with the rotation center P of the lock claw 4. Therefore, the elastic repulsive force Z of the lock spring 6 cannot become a force that rotates the lock claw 4, and the rotation biasing force from the lock spring 6 does not act on the lock claw 4. Note that when the lock claw 4 rotates in the protruding direction from the rotation position Q0 which is the consideration point, as shown in Fig. 12(a), the line of action N indicating the direction of the elastic repulsive force Z of the lock spring 6 moves to the right of the rotation center P of the lock claw in the figure, and a rotation moment in the clockwise direction in the figure acts on the lock claw 4. On the other hand, when the locking claw 4 rotates in the retraction direction from the rotation position Q0 which is the consideration point, as shown in FIG. 12(c), the line of action N indicating the direction of the elastic repulsive force Z of the locking spring 6 moves to the left of the rotation center P of the locking claw 4 in the figure, and a rotational moment acts on the locking claw 4 in the counterclockwise direction in the figure.That is, the rotation range of the locking claw 4 is divided into a protruding / retracting operating region R1 from a rotation position Q0, which is the consideration point, to a most protruding position Q1, and a retracting region R2 from the rotation position Q0, which is the consideration point, to a retracted position Q2, and the locking spring 6 is arranged so as to urge the locking claw 4 to rotate in the protruding direction (clockwise direction in the figure) in the protruding / retracting operating region R1, and to urge the locking claw 4 to rotate in the retracting direction (counterclockwise direction in the figure) in the retracting region R2. That is, the locking spring 6 serves both to elastically urge the locking claw 4 in the protruding direction to disengage it from the claw engaging portion 7 when the top board 1 is raised, and to stably hold the locking claw 4 in the retracted position Q2 when the top board 1 is lowered.

[0034] 6, 9, 11, and 13 to 15, a claw retraction element is provided at the upper end of the claw receiving member 8, which utilizes the upward movement of the upper cylinder 211 to guide the lock claw 4 from the projection / retraction operating region R1 to the retraction region R2 before the relative movement between the upper leg element 21 and the lower leg element 22 of the leg body 2 reaches a relative position where the relative movement ends, i.e., before the upper cylinder 211 reaches the top dead center U. The claw retraction element includes a lower projection 82 that is protruded directly above the uppermost claw engagement portion 5 of the claw receiving member 8 and guides the front surface 4b of the upwardly moving lock claw 4 to push back the lock claw 4 in the retraction direction, and an upper projection 83 that is provided above the lower projection 82 and engages the front projection 46 of the upwardly moving lock claw 4 to forcibly rotate the lock claw 4 to the retracted position Q2.

[0035] 6, 9, 11, and 13 to 15, a claw return element is provided on the lower end side of the claw receiving member 8, which uses the downward movement of the upper cylinder 211 to guide the locking claw 4 from the retraction region R2 to the protruding / retracting operation region R1 before the relative movement between the upper leg element 21 and the lower leg element 22 of the leg body 2 returns to the relative position which is the starting point, that is, before the upper cylinder 211 reaches the bottom dead center D. The claw return element is composed of an inclined protrusion 84 cut and raised from the claw receiving member 8, and this inclined protrusion 84 is shaped to gradually rise toward the claw holding member 7.

[0036] Next, the operation of this ratchet device X will be described with reference to FIGS.

[0037] 13(a) shows a state in which the claw holding member 7 (first member) provided on the upper leg element 21 of the leg body 2 and the claw receiving member 8 (second member) provided on the lower leg element 22 of the leg body 2 are stopped at a relative position that is the starting point, in other words, a state in which the upper cylinder 211 supporting the tabletop 1 has descended to the bottom dead center D relative to the lower cylinder 221 supported on the floor surface F, and the tabletop 1 is held in the lowest position (H720). In this state, as also shown in FIG. 14, the lock claw 4 is in the protruding / retracting operating region R1 and is elastically biased in the protruding direction by the lock spring 6 to engage with the lowest-stage claw engagement part 5.

[0038] When the top plate 1 is lifted upward from this state, the lock claw 4 rises while the front surface 4b slides against the upper side 52 of the claw engagement portion 5. As a result, the lock claw 4 is gradually pushed back in the retracting direction against the biasing force of the lock spring 6 and disengages from the claw engagement portion 5. FIG. 13(b) shows the state in which the lock claw 4 has disengaged from the lowest claw engagement portion 5 and further risen. Even in this state, the lock claw 4 is in the protruding / retracting operating region R1 and is biased in the protruding direction by the elastic repulsive force of the lock spring 6. Therefore, the lock claw 4 rises while the tip portion 41 elastically contacts the claw receiving member 8.

[0039] When the locking claw 4 rises further and reaches the next-stage claw engagement portion 5, as shown in Fig. 13(c), the locking claw 4 rotates in the protruding direction due to the elastic force of the locking spring 6 and engages with the next-stage claw engagement portion 5. In this state, the claw holding member 7 is locked to the claw receiving member 8, and the upper leg element 21 of the leg body 2 is prohibited from descending, so that the tabletop 1 is held in the middle position (H800) even if the tabletop 1 is released.

[0040] When the tabletop 1 is lifted further upward from this state, the locking claw 4 disengages from the next-stage claw engagement portion 5 through a similar operation and engages with the top-stage claw engagement portion 5 as shown in Fig. 13(d). Even in this state, the claw holding member 7 is locked to the claw receiving member 8, and the upper leg element 21 of the leg body 2 is prevented from descending, so the tabletop 1 is held in the upper stage position (H900) even if it is released.

[0041] When the tabletop 1 held at the upper position (H900) is further raised, the lock claw 4 rises while the front surface 4b slides against the lower projection 82 of the claw receiving member 8, and the lock claw 4 is pushed back to the vicinity of the rotation position Q0, which is the locking point. Then, when the lock claw 4 rises further and the upper cylinder 211 reaches the top dead center U, as shown in Fig. 13(e), the front projection 46 of the base end portion 42 is locked by the upper projection 83 of the claw receiving member 8, and the lock claw 4 is rotated beyond the rotation position Q0, which is the locking point, to the retracted position Q2, and is held at the retracted position Q2. This state is also shown in Figs. 15(a) and (b).

[0042] In the state where the locking claw 4 is held in the retracted position Q2, the upper leg element 21 of the leg 2 having the claw holding member 7 can be lowered in one go to the bottom dead center D together with the tabletop 1 by loosening or eliminating the lifting force on the tabletop 1. In other words, the claw holding member 7 (first member) and the claw receiving member 8 (second member) can be returned in one go to the relative position (bottom dead center D) that is the starting point without being locked on the way. FIG. 13(f) shows the state immediately before returning to the relative position (bottom dead center D) that is the starting point, and the tip 41 of the locking claw 4 held in the waiting position Q2 descends toward the inclined protrusion 84 of the claw receiving member 8. When the locking claw 4 further descends from this state, the tip 41 of the locking claw 4 is guided by the inclined protrusion 84 and is urged to rotate forward, and is guided beyond the rotation position Q0 that is the thinking point into the protruding and retracting operating region R1. The locking claw 4 that has entered the protruding / retracting operating range R1 is urged to rotate in the protruding direction by the elastic biasing force Z of the locking spring 6, and as shown in Figures 13(a), 14(a) and (b), it engages with the lowest claw engagement portion 5 and returns to its original relative position as the starting point (the position where the upper cylinder 211 reaches the bottom dead center D).

[0043] The ratchet devices X described above are incorporated into the left and right legs 2, so that, for example, if two people lift and operate both left and right ends 1a, 1b of the tabletop 1, the ratchet devices X of the left and right legs 2 will perform the same movement, and the tabletop 1 can be locked successively at the lowest position (H720), the middle position (H800), and the upper position (H900) while keeping the tabletop 1 horizontal, and the tabletop 1 can be returned to the lowest position (H700). However, in this table T, not only are the ratchet devices X independently incorporated into the left and right legs 2, but the lower leg elements 22 of the left and right legs 2 are not connected to each other, so that the height of the tabletop 1 can be adjusted by one person.

[0044] When adjusting the height of the tabletop 1 by oneself, for example, the right end 1a of the tabletop 1, which is in the lowest position (H720) as shown by the solid lines in Fig. 1 and Fig. 2 and Fig. 21, is first lifted. This operation extends only the right leg 2, which is locked in the middle position (H800) as shown in Fig. 16. After that, when the left end 1b of the tabletop 1, which remains in the lowest position (H720), is lifted, the left leg 2 is also extended and the left side of the tabletop 1 is locked in the middle position (H800), and the tabletop 1 becomes horizontal as shown in Fig. 17. If it is desired to use the tabletop 1 in the middle position (H800), the height adjustment is completed at this stage.

[0045] When it is desired to use the tabletop 1 in the upper position (H900), for example, the right end 1a of the tabletop 1 in the middle position (H800) shown in Fig. 17 is first lifted. This operation extends only the right leg 2, and it is locked in the upper position (H900) as shown in Fig. 18. After that, when the left end 1b of the tabletop 1 remaining in the middle position (H800) is lifted, the left leg 2 also extends, and the left side of the tabletop 1 is also locked in the upper position (H900), and the tabletop 1 becomes horizontal as shown in Fig. 19.

[0046] When it is desired to return the tabletop 1 from the state where it is used in the upper stage position (H900) to the lowest stage position (720), as shown in FIG. 20, first, the right end portion 1a of the tabletop 1 is lifted slightly to release the locked state of the ratchet device X incorporated in the right leg 2, and the right end portion 1a of the tabletop 1 is lowered while the locking claw 4 is held in the retracted position Q2. After that, the left end portion 1b of the tabletop 1 remaining in the upper stage position (H900) is lifted slightly to release the locked state of the ratchet device X incorporated in the left leg 2, and the left end portion 1b of the tabletop 1 is also lowered while the locking claw 4 is held in the retracted position Q2. By this operation, the entire tabletop 1 can be returned to the initial state where it is held horizontally in the lowest stage position (H720). In this embodiment, a damper 75 is provided on the claw support member 7, and in the latter half of the operation of lowering the claw support member 7 toward the bottom dead center D, the tip 77a of the protruding rod 77 of the damper 75 is engaged by a damper engaging plate 85 provided at the lower end of the claw receiving member 8, thereby preventing the top plate 1 from descending rapidly and causing an impact.

[0047] By repeating the above operations, even one person can freely set the height position of the tabletop 1. During the height adjustment of the tabletop 1, the tabletop 1 tilts, and the upper leg elements 21 of the legs 2 assembled perpendicularly to the tabletop 1 and the lower leg elements 22 of the legs 2 held by these upper leg elements 21 so as to be able to move up and down will tilt with respect to the floor surface F. However, since the lower leg elements 22 of the left and right legs 2 are not connected to each other and are open, even if the degree of expansion and contraction of the left and right legs 2 temporarily differs, the movement can be accommodated without difficulty.

[0048] Here, FIG. 1 is a perspective view showing the lift-up table T of this embodiment. FIG. 2 is a front view showing the lift-up table T. FIG. 3 is a bottom view showing the lift-up table T. FIG. 4 is a right side view showing the lift-up table T. FIG. 5 is an exploded perspective view showing the connection between both legs 2 and the connecting beam 3. FIG. 6 is an enlarged central vertical sectional view of a portion including the ratchet device X of the lift-up table T cut at the center in the depth direction. FIG. 7 is a sectional view taken along line AA in FIG. 6. FIG. 8 is a sectional view taken along line BB in FIG. 6. FIG. 9 is an enlarged perspective view of a portion including the ratchet device X of the lift-up table T, showing the leg body 2 and the ratchet device X in a cutaway view. FIG. 10 is a perspective view showing the ratchet device X taken out. FIG. 11 is an exploded perspective view showing the ratchet device X of the lift-up table T. FIG. 12 is an explanatory view showing the action of the lock spring 6 of the ratchet device X of the lift-up table T. Fig. 13 is an explanatory diagram showing the operation of the ratchet device X of the lift-up table T, and (a) to (f) in the figure respectively show a state in which the tabletop 1 is locked at the lowest stage position (H720) (bottom dead point D), a state in which the tabletop 1 is located between the lowest stage position (H720) and the middle stage position (H800), a state in which the tabletop 1 is locked at the middle stage position (H800), a state in which the tabletop 1 is locked at the upper stage position (H900), a state in which the tabletop 1 has risen beyond the upper stage position (H900) and reached the top dead point U, and a state in which the tabletop 1 has descended from the top dead point U and is about to reach the lowest stage position (H720) (bottom dead point D). (a) in Fig. 14 is an enlarged central vertical cross-sectional view of a portion including the ratchet device X of the lift-up table T in a state in which the tabletop 1 is locked at the lowest stage position (H720) (bottom dead point D), cut at the center in the depth direction. FIG. 15(b) is an enlarged perspective view of a portion including the ratchet device X, with the leg body 2 and the ratchet device X cut away. FIG. 15(a) is an enlarged central vertical cross-sectional view of a portion including the ratchet device X of the lift-up table T cut at the center in the depth direction when the top plate 1 has reached the top dead center U. FIG. 15(b) is an enlarged perspective view of a portion including the ratchet device X, with the leg body 2 and the ratchet device X cut away. FIG. 16 is a schematic front view showing a state in which the right end 1a of the top plate 1 of the lift-up table T is locked in the middle position (H800) and the left end 1b is locked in the lowest position (H720).FIG. 17 is a schematic front view showing a state in which both the left and right end portions 1a and 1b of the top plate 1 of the lift-up table T are locked in the middle stage position (H800). FIG. 18 is a schematic front view showing a state in which the right end portion 1a of the top plate 1 of the lift-up table T is locked in the upper stage position (H900) and the left end portion 1b is locked in the middle stage position (H800). FIG. 19 is a schematic front view showing a state in which both the left and right end portions 1a and 1b of the top plate 1 of the lift-up table T are locked in the upper stage position (H900). FIG. 20 is a schematic front view showing a state in which the right end portion 1a of the top plate 1 of the lift-up table T is locked in the lowermost stage position (H720) and the left end portion 1b is locked in the upper stage position (H900). FIG. 21 is a schematic front view showing a state in which both the left and right end portions 1a and 1b of the top plate 1 of the lift-up table T are locked in the lowermost stage position (H720).

[0049] In a lift-up table having such a configuration, the lower leg elements 22 of the left and right leg bodies 2 are not connected to each other, and can tilt independently with respect to the floor surface F. Therefore, even if the manual ratchet devices X built into the left and right leg bodies 2 move differently from each other, the tabletop 1 and both leg bodies 2 only tilt slightly with respect to the floor surface F while maintaining an orthogonal relationship, and the upper leg element 21 can be smoothly raised and lowered with respect to the lower leg element 22.

[0050] In other words, if the left and right lower leg elements are rigidly connected to each other by sturdy cross members or the like and stand perpendicular to the floor surface, if the left and right upper leg members are not raised and lowered precisely in sync so that the tabletop remains horizontal at all times, a force will act between the lower leg element and the upper leg element to cause the axes to shift, resulting in friction when they slide relative to each other. However, in this lift-up table T, the left and right lower leg elements 22 are not restrained from each other and can each tilt freely relative to the floor surface F, so that even if there is a slight difference in the lifting and lowering movement of the left and right upper leg elements 21, friction between the upper leg element 21 and the lower leg element 22 can be prevented or suppressed.

[0051] Therefore, even when two people adjust the height by lifting both ends of the tabletop 2, there is no need to precisely move the tabletop 1 horizontally and precisely synchronize the left and right ratchet devices X, and the tabletop 1 can be smoothly locked at the desired height with rough operation. Moreover, with such a configuration, temporary tilting of the tabletop 1 is permitted, so that one person can adjust the height of the tabletop 1 by alternately operating the ends 1a and 1b of the tabletop 1, as shown in Figures 15 to 20.

[0052] Furthermore, if conventional thinking is followed to connect the lower leg elements of the left and right legs with a highly rigid structural material, it is difficult to realize a structure that allows the lift-up table to be moved easily and stacked; however, with this lift-up table T, there are no members near the floor surface F that rigidly connect the lower leg elements 22, thereby improving the design freedom to meet such demands.

[0053] Of course, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0054] For example, the ratchet devices provided on both legs are not limited to those in the above embodiment, and may be ones that perform unlocking by a special external operation. However, in the ratchet device X configured as described above, the lock spring 6 serves both the role of elastically biasing the lock claw 4 in the protruding direction to engage and disengage the lock claw 4 from the claw engagement portion 7 when the tabletop 1 is raised, and the role of stably holding the lock claw 4 in the retracted position Q2 when the tabletop 1 is lowered. This allows the number of parts to be reasonably reduced, and the man-hours required for manufacturing the parts and the man-hours required for assembly can be reduced.

[0055] In particular, in the embodiment, the claw receiving member 8 in which the claw engagement portion 5 is formed is integrally provided with the claw retraction elements (lower protrusions 82, upper protrusions 83) for moving the locking claw 4 from the protruding / retracting operation region R1 to the retraction region R2, the claw return elements (inclined protrusions 84) for returning the locking claw 4 from the retraction region R2 to the protruding / retracting operation region R1, and the damper locking plate 85, making it possible to reduce the number of parts to an absolute minimum.

[0056] The legs are not limited to those having casters at the lower ends, and may be those having adjusters, for example. In the case of adjusters, it is preferable that the adjuster of at least one of the legs is one that slides easily on the floor surface. In addition, if casters with a braking function are used, it is preferable to temporarily release the braking of the caster of at least one of the legs when adjusting the height of the tabletop.

[0057] Furthermore, the lift-up table in the above embodiment has a structure that allows the top plate to perform a flapping operation, but the present invention can also be applied to a lift-up table in which the top plate and legs are fixed.

[0058] In addition, various modifications may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0059] T…Lift table 1…Tabletop 1a...Left end 1b...Right end 2…Leg body 21...Upper leg element 211...Upper tube 22...lower leg element 221…Lower cylinder 224…Leg base 23...Rotation prevention means 3…Connecting beam X…Ratchet device F…Floor surface

Claims

1. A lift-up table in which both left and right ends of a tabletop are supported by legs, each of which has an upper leg element and a lower leg element that move relative to each other in the up-down direction, and each of which is equipped with a manual ratchet device that allows the tabletop to be sequentially locked at a plurality of height positions by lifting the tabletop, The left and right legs are rigidly connected to each other only in their upper leg elements, and the lower leg elements are not rigidly connected to each other and can be tilted independently relative to the floor surface.

2. A lift-up table as described in claim 1, wherein the leg body is formed by telescopically engaging an upper tube and a lower tube, the upper leg element being mainly constituted by the upper tube, and the lower leg element being mainly constituted by the lower tube and a leg base provided at the lower end of the lower tube.

3. 3. A lift table according to claim 2, wherein the upper cylinders of the left and right legs are rigidly connected to each other by a connecting beam.

4. 4. A lift-up table according to claim 2 or 3, wherein the lower cylinders of the left and right legs are constructed so as to be able to tilt together with the leg bases in the left and right directions with respect to the floor surface.

5. 5. A lift table according to claim 2, further comprising a rotation prohibiting means for prohibiting the upper cylinder and the lower cylinder from rotating relative to each other about their respective axes.

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