JPH10276840A - Lifting device for wagon desk with raisable top board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lifting device such that a raisable top board can be adjusted in height in a number of steps at practically permissible intervals and be securely supported, and that cost is reduced through the simplification of a mechanism. SOLUTION: A hollow support rod 8 secured to a raisable top board 5 at its upper end is vertically movably passed through a hollow guide rod 7 vertically provided inside each side plate of a main body portion 2, and a control rod 19 which only moves up and down as a control lever 18 placed near the lower surface of the raisable top board 5 is operated is vertically placed inside the support rod 8. An engaging member 21 from one side of which an engaging claw is projected is placed in the lower portion of the inside of the support rod 8 in such a way as to be capable of being slid horizontally by a guide member 20 secured to the support rod 8, a pin 26 projected from the control rod 19 is engaged in an inclined oblong hole formed in the engaging member, and the engaging member is elastically energized so that the engaging claw is passed through the support rod 8, projected, and engaged in each of engaging holes 14 formed in the side face of the guide rod 7 at equal intervals along the vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device for a wagon desk with a lifting table, and more particularly, to a lifting table supported on a fixed top plate of a wagon desk body so as to be adjustable in height. The present invention relates to an elevating device for a wagon desk with an elevating top plate.

[0002]

2. Description of the Related Art Conventionally, a movable wagon desk of this kind is used in combination with a flat desk, and is arranged close to one leg plate between both leg plates of the flat desk to form a desk with sleeves. Or, it is installed outside the leg plate and used as a side desk. In a learning desk for school children, this type of separation type is the mainstream in recent years. However, if the height of the top plate of the wagon desk is fixed so that it can be accommodated between the two legs of the flat desk, if it is arranged outside the legs of the flat desk and used as a side desk, The height of the top plate is too low, making it inconvenient for normal use.

[0003] Therefore, the height of the top plate of the wagon desk,
There are two stages: a low state where it can be placed between the two leg boards of the flat desk, and a high state where it is located at the same height as the desk top plate so that it can be used as a side desk by being placed outside the leg plate of the flat desk. In order to enable setting, a structure in which an elevating top plate is connected to a main body via a link type elevating mechanism has been provided.

[0004] However, the conventional wagon desk with a lift top plate has a poor external appearance and poor operability because the lift mechanism is provided between the fixed top plate of the main body and the lift top plate. There was a risk of stuffing fingers in the mechanism. On the other hand, the present applicant has built in an elevating device having a ratchet type stopper mechanism in both side plates of the main body, and provided at the upper end of a supporting member constituting the elevating device protruding from both sides of the fixed top plate of the main body. There is provided a structure in which an elevating top plate is fixed and the height of the elevating top plate can be finely adjusted in a multi-stage manner but substantially continuously.

[0005]

However, the lifting device having the ratchet type stopper mechanism proposed by the present applicant is excellent in operability and adjustability from the viewpoint of adjusting the height of the lifting top plate. However, there is no need to adjust the height of the elevating table so finely, so that a feeling of excessive function cannot be denied.

In view of the above situation, the present invention is intended to solve the problem by adjusting the height of the elevating table in multiple steps at intervals that are practically inconvenient, and ensuring the support of the elevating table. It is another object of the present invention to provide a lifting / lowering device for a wagon desk with a lifting / lowering top plate, which can be simplified and the mechanism is simplified to reduce the cost.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a lift top plate having a height adjustable support provided above a fixed top plate of a wagon desk main body. With a lifting device of a wagon desk, a hollow support rod having an upper end fixed to the lift top plate is vertically movably inserted into a hollow guide rod vertically provided in both side plates of the main body, An operating rod that only moves up and down in conjunction with the operation of an operating lever disposed near the lower surface of the elevating top plate is vertically arranged in the supporting rod, and a lower part of the supporting rod is provided with the operating rod. An engaging member having an engaging claw protruding on one side by a fixed guide member is disposed so as to be slidable in the lateral direction, and a pin protruding from the operating rod is engaged with an oblong slot formed in the engaging member. And the engaging pawl projects through the support rod and moves up and down on the side of the guide rod. The engaging member is elastically urged to engage with the engaging holes formed at regular intervals in the direction, the operating lever is operated by operating the operating lever, and the pin and the oblong slot are moved relative to each other. By changing the position, the engaging member is slid and disengaged from the engaging claw and the engaging hole to constitute a lifting device of a wagon desk with a lifting top plate.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG. 1 shows a wagon desk 1. The wagon desk 1 is provided with a lifting top plate 5 supported by a lifting device 4 so as to be adjustable in height above a fixed top plate 3 of a box-shaped main body 2 having an open front. It is provided.

More specifically, the wagon desk 1 comprises:
The guide rods 7 of the left and right elevating devices 4 are built in the inside of both side plates 6 and 6 of the main body 2, respectively, and a support rod 8 supported at a predetermined position by the guide rods 7 is inserted thereinto. The supporting rods 8, 8 projecting upward from both upper ends of the support rods
Has a structure in which the elevating top plate 5 is fixed to the upper end portion of the upper and lower ends. Are provided in the main body 2 in multiple stages and casters 10,... Are provided at the four corners at the lower end so as to be movable, and the lower surface of the lower end of the drawer 9 is also prevented from tipping over. Casters 11 are provided.

As shown in FIGS. 2 to 7, the elevating device 4 includes a vertical groove 1 vertically provided along the inner surface of the side plate 6.
A guide rod 7, which is fixed without protruding to the inner surface inside 2,
A hollow support rod 8, which is vertically inserted into the guide rod 7 and whose upper end is fixed to the elevating top plate 5, and the guide rod 7
And a stopper mechanism 13 for fixing the supporting rod 8 at a predetermined height position. The left and right lifting devices 4 and 4 are mirror symmetric.

The guide rod 7 is an elongated member having a substantially C-shaped cross section and having an angular shape, and is provided on both side edges of a substrate 7A having a width slightly smaller than the width of the vertical groove 12.
Are formed by bending side plates 7B, 7B having substantially the same width as the depth of each of the plates, and further bending plates 7C, 7C at right angles to the edges of both side plates 7B, 7B to approach each other. A predetermined interval is provided between the two bent plates 7C. In the side plates 7B, engaging holes 14,... Are formed at regular intervals in the vertical direction, and fitting holes 15, 15 are formed in upper and lower ends. In this embodiment,
Since the pitch of the engaging holes 14,... Is set to 15 mm, the height of the elevating top plate 5 can be adjusted at intervals of 15 mm.

The supporting rod 8 is formed by superposing two long constituent members 16 and 17 having a substantially U-shaped cross section on each other to form a flat hollow cylinder with a hollow inside. In consideration of the above, it is set longer than the guide rod 7. One of the component members 16 is formed by bending overlapping plates 16B, 16B at right angles to both side edges of the substrate 16A, and a notch 16C is formed at the upper end of the one overlapping plate 16B corresponding to the front side of the wagon desk 1 in the vertical direction. Notch 16 at lower part near center
D, a part of the substrate 7A is cut and raised inside at a height position between the notches 16C and 16D to form a protruding piece 16E, and a horizontally long part is formed at the center of the lower end of the substrate 7A. In this case, a circular hole 16F is formed. The other component member 17 is formed by bending overlapping plates 17B, 17B at right angles to both side edges of the substrate 17A.
7B, notches 17C, 17D are formed at positions corresponding to the notches 16C, 16D, and circular holes 17E, 17E are formed on both sides of the lower end of the substrate 17A. The superposed plates 17B, 17B are provided on the outer surfaces of the superposed plates 16B, 16B.
The two components 16 and 17 are superposed and fixed in a state where the components 17B are overlapped, and the inside is made hollow.

The stopper mechanism 13 includes an operating lever 18 provided mostly inside the support rod 8 and disposed near the lower surface of the elevating and lowering plate 5;
8, an operating rod 19 that only moves up and down in conjunction with the operation of 8, a guide member 20, an engaging member 21 that is guided by the guide member 20 and is slidable in the horizontal direction, and an elastic urging unit 22. ing.

The operating lever 18 is pivotally supported by a support shaft 23 having a base end fixed to the rear side of the substrates 16A, 17A inside the support rod 8, and the both cutouts 16 are provided.
C and 17C are led forward along the lower surface of the elevating top plate 5 from the openings formed by C and 17C.

The operating rod 19 is a long plate-like member.
A bent piece 24 is formed at the upper end to be engaged with the operation lever 18, and a slit hole 25 is formed at an upper and lower middle part for receiving the protruding piece 16E and guiding it so that it can only move up and down. 26, and a long hole 27 is formed near the pin 26 and extends upward and downward. The operating rod 19 is bent at the upper part, the upper part is along the front side of the supporting rod 8, and the lower part is along the front and rear central part of the supporting rod 8.

The upper and lower portions of the guide member 20 are fixed to the lower portion of the support rod 8 by two caulking pins 28 penetrating the substrates 16A, 17A.
An engaging member 2 to be described later is provided at an intermediate position
Guide recess 29 for guiding slide 1 so that it can slide laterally
And a regulating projection 3 projecting from the upper and lower portions of the guiding recess 29.
0,..., The vertically extending elongated holes 31 for receiving the pins 26 protruding from the operating rod 19 as appropriate are formed in the guide recesses 2.
9 is formed at the center.

The engaging member 21 is a flat plate-like member, and is guided in the guiding recess 29 of the guide member 20 so as to be slidable in the lateral direction while being prevented from being pulled out by the regulating protrusions 30,. An engaging claw 32 is protruded from one side, and a slanted elongated hole 33 is formed at a substantially central portion. The engaging claw 32 projects from an opening formed by both the cutouts 16D and 17D of the support rod 8.

In the present embodiment, the elastic biasing means 22 is constituted by a kick spring, and the tip of one spring piece 22B extending from the coil spring portion 22A is fixed to the locking portion 1 of the component member 16.
6G, the tip of the other spring piece 22B is locked in a locking recess 21A on the side edge of the engagement member 21, and the engagement claw 32 of the engagement member 21 is fixed to the side surface of the support rod 8. It is elastically biased in a direction to protrude from the front. The elastic urging means 22 can be constituted by a compression coil spring, a leaf spring or the like other than the kick spring described above.

In a state where the two constituent members 16 and 17 constituting the supporting rod 8 are separated, the caulking pin and the caulking pin 28 serving as the support shaft 23 are removed at a predetermined position on the substrate 16A of one of the constituent members 16. After inserting the shaft hole 18A at the base end of the operation lever 18 through the support shaft 23 and positioning the center portion in the notch portion 17C,
The operating rod 19 is inserted into the slit hole 25 through the protruding piece 16E, the bent piece 24 is locked to the operating lever 18, and the long hole 27 is inserted into the upper caulking pin 28. Then, the guide recess 20 is provided in the guide member 20.
The support holes 20A, 20A of the guide member 20 are mounted with the engagement member 21 mounted using the
Is inserted through the two caulking pins 28, 28, and the oblong elongated hole 33 of the engaging member 21 is inserted through the pin 26 of the operating rod 19. At this time, in order to make the lower end of the operating rod 19 and the engaging member 21 intersect closely, the guide member 20 has a stepped portion 20B for receiving the operating rod 19. Further, the pin 26 is connected to the oblong slot 33 of the engagement member 21.
When the pin 26 is set slightly longer so as to protrude from the engagement member 21 in a state where the pin 26 is inserted into the guide member 20, the protrusion of the pin 26 is received in the elongated hole 31 of the guide member 20. After each member is set in this way, the other component member 17 is externally fitted to the component member 16 and the two component members 16 and 17 are joined by caulking each caulking pin to form the support rod 8.

Here, the direction of the oblong slot 33 formed in the engaging member 21 is set so as to be inclined from the upper front to the lower rear at an angle of about 45 degrees. In addition, the operating rod 19
Is guided by the protruding piece 16E, the slit hole 25 and the elongated hole 27 and the caulking pin 28 so as to move only up and down. Thereby, the operation lever 18 is lifted,
When the operating rod 19 is moved upward, the pin 26 and the oblong elongated hole 33 change their relative positions, so that the engaging member 21 is guided by the guide member 20, and the engaging claw 32 is pulled into the supporting rod 8. The slide moves. Then, the supporting rods 8, 8 are inserted into the guide rods 7, 7 fixed in the vertical grooves 12 of the side plates 6, 6 from above and assembled. Here, in order to fix the guide rod 7 to the side plate 6, as shown in FIGS. 2 and 6, the guide rod 7 is inserted into a predetermined position in the vertical groove 12 from the substrate 7A side, and then the guide rod 7 is inserted. 7 and fixing brackets 34, 34
Is screwed to the inner surface of the side plate 6 and the guide rod 7
To the two bent plates 7C, 7C.

FIG. 5 shows that the engaging claw 32 of the engaging member 21 protrudes from the side surface of the supporting rod 8 by the elastic urging force of the elastic urging means 22 so that any one of the engaging holes of the guide rod 7 is engaged. 14 and a predetermined height (lowest in the figure)
3 shows a state in which the elevating top plate 5 is maintained. If the palms of both hands are placed on both sides of the elevating table 5 and the fingers are simultaneously put on the operation levers 18 and 18 and the operation levers 18 on both sides are simultaneously lifted as described above, as shown in FIG. As described above, the engagement between the engagement claw 32 and the engagement hole 14 is released, and in this state, the lifting top plate 5 is lifted,
Alternatively, when the finger is released from the operation levers 18 and 18 after being adjusted to a predetermined height by pressing down, the engagement claws 32 are engaged with the engagement holes 14 by the elastic urging force of the elastic urging means 22, and 5 is maintained at the adjusted height. Here, since the engaging member 21 is moved only in the lateral direction by the guide member 20, a vertical force is applied to the supporting rod 8 in a state where the engaging claw 32 is engaged with the engaging hole 14. It is extremely stable.

Further, the lifting device 4 according to the present invention will be described. An upper slider 35 and a lower slider 36 are fitted to the upper and lower ends of the guide rod 7, respectively, and the support rod 8 is smoothly moved without rattling. A stopper 37 is fitted on the lower end of the supporting rod 8 which is supported so as to be able to move up and down and penetrates below the guide rod 7 and which abuts on the lower slider 36 when it is raised most.

The upper slider 35 is connected to the guide rod 7
As shown in detail in FIG. 9, a flange portion 3 is provided around an opening at one end of a cylindrical portion 35A through which the support rod 8 is inserted and which is fitted into the guide rod 7 as shown in detail in FIG.
5B, and a claw 35C that fits into the one fitting hole 15 of the guide rod 7 from inside is protruded from one short side surface of the cylindrical portion 35A, and the other short side of the cylindrical portion 35A is formed. A spacer portion 35D is extended from the flange portion 35B at an interval to the side surface and fitted into the other fitting hole 15 of the guide rod 7 from the outside toward the short side surface side of the spacer portion 35D. The protruding claw 35E is provided.

As shown in detail in FIG. 10, the lower slider 36 has the same shape as the upper slider 35 which is turned upside down. The lower slider 36 is inserted through the support rod 8 and fits inside the guide rod 7. A flange 36B is formed around one end opening of the cylindrical portion 36A, and the cylindrical portion 36A is formed.
A, one fitting hole 1 of the guide rod 7
5 is provided with a claw 36C to be fitted from inside, and a cylindrical portion 36A is provided.
A gap is provided with respect to the other short side surface of the
B, a spacer portion 36D is extended from the spacer portion 3D.
A claw 36E that fits from the outside into the other fitting hole 15 of the guide rod 7 projects toward the short side surface side of 6D.

Then, the guide rod 7 is fitted into the vertical groove 12 of the side plate 6 with the upper slider 35 and the lower slider 36 fitted above and below the guide rod 7. In this case, as shown in FIGS. 4 and 5, the spacer portion 35D of the upper slider 35 and the spacer portion 3 of the lower slider 36
6D, a space is formed between the side surface of the guide rod 7 and the inner wall of the vertical groove 12, and even if the tip of the engaging claw 32 engaged with the engaging hole 14 projects from the engaging hole 14, It is possible to escape by space.

The stopper 37 is fitted to the lower end of the support rod 8, and has flanges 37 on both sides of the base end side of the insertion section 37A having a U-shaped cross section to be inserted into the support rod 8.
B and 37B are extended, and flange portions 37C that abut against the end surfaces of the support rods 8 are respectively protruded from ends of the insertion portion 37A and both flange portions 37B and 37B.
The semi-circular projections 37D, 37D fitted into the arc portions of the oblong holes 16F protrude from the surface of the component member 16 which comes into contact with the substrate 16A, and come into contact with the substrate 17A of the component member 17 of the flange portions 37B, 37B. Circular projections 37E, 37E to be fitted in the circular holes 17E, 17E are respectively provided on the contacting surfaces, and furthermore, between the two semicircular projections 37D, 37D, there are inclined surfaces downward and steep locking surfaces upward. A stopper claw 37F having elasticity is provided on the inside and outside to protrude outward. And stopper 3
7 is fitted into the lower end of the support rod 8, but in the fitted state, the flange 37C does not protrude from the support rod 8 to the periphery, and only the stopper claw 37F protrudes from the center of the oblong hole 16F.

When the support rod 8 with the stopper 37 fitted to the lower end thereof is inserted from above the guide rod 7, first, the stopper claw 37F is elastically deformed so that the cylindrical portion 35A of the upper slider 35 is elastically deformed. Passing, guide rod 7
Between the two folded plates 7C, 7C, and then the lower slider 3
6, the assembly of the support rod 8 with the guide rod 7 is completed. After the assembly is completed, when the support rod 8 is pulled up to the uppermost position with respect to the guide rod 7, the steep locking surface of the stopper claw 37F of the stopper 37 abuts against the flange portion 36B of the lower slider 36, and no longer passes. Since the support rod 8 cannot be removed from the guide rod 7, there is no possibility that the support rod 8 will fall out.

Further, in order to fix the elevating top plate 5 to the upper end of the supporting rod 8, as shown in FIGS. 1, 4 and 6, it is fixed via a mounting bracket 38. This mounting bracket 38
Has a mounting plate 38A extending in the front-rear direction for screwing to the lower surface of the elevating top plate 5, and the mounting plate 3
8A has an arm plate 38B extending laterally from the front-rear central portion, and the outer end of the arm plate 38B is bent downward to fix the fixing plate 38C and a part of the arm plate 38B to raise and lower a fixing piece 38.
D is formed so as to be parallel to the fixing plate 38C, and further, the inside end of the mounting plate 38A is bent downward to form a reinforcing piece 38E. Further, the rear end of the fixing plate 38C is bent inward to form a stop piece 38F. Then, the upper end of the supporting rod 8 is fixed to the fixing plate 38C and the fixing piece 3.
With the screw 38G inserted from the fixing plate 38C penetrating the supporting rod 8 and screwing into the fixing piece 38D while being inserted between the 8D and being in contact with the fixing piece 38F, the screw 38G is inserted into the fixing piece 38F. Is screwed into the supporting rod 8 and fixed. The reference numeral 38H in FIG. 6 denotes the mounting plate 38A.
Are attached to the lower surface of the elevating top plate 5.

Also, when the elevating table 5 is lowered to the lowest position, the lower four corners of the elevating table 5 are so fixed that a finger is not caught between the elevating table 5 and the fixed table 3. Are provided so as to protrude from each other to form a finger jam prevention space between the elevating and lowering top plate 5 and the fixed top plate 3. here,
The downward reinforcing piece 38 </ b> E of the mounting bracket 38 is set at a sufficiently inward position where a finger cannot reach from a side end of the elevating top plate 5.

Finally, a personal computer is often mounted on the upper surface of the elevating table 5, and in that case, a space for operating the mouse cannot be secured. Therefore, as shown in FIG. The mouse board 40 is provided on the lower surface of the elevating top plate 5 and between the mounting plates 38A, 38A of the mounting brackets 38, 38 so as to be able to be pulled out forward. For example, a rail plate 41 is formed by bending the lower end of the reinforcing piece 38E of the mounting bracket 38 inward, and the mouse board 40 is slidably mounted on the rail plates 41, 41 of the mounting brackets 38, 38. Just do it. In order to support the mouse board 40 so that the mouse board 40 can be pulled out, other structures can naturally be adopted.

[0031]

According to the lifting apparatus for a wagon desk with a lifting table of the present invention as described above, a lifting table supported in a height-adjustable manner is provided above the fixed top of the wagon desk main body. A lifting device for a wagon desk with a lifting top plate, wherein a hollow supporting rod body having an upper end fixed to the lifting top plate can be vertically moved to a hollow guide rod vertically provided in both side plates of the main body. In the support rod, an operation rod that only moves up and down in conjunction with the operation of an operation lever disposed near the lower surface of the elevating top plate is vertically disposed, and a lower part of the support rod is An engaging member having an engaging claw protruding on one side by a guide member fixed to the supporting rod is slidably disposed, and a pin protruding from the operating rod is formed on the engaging member. The engaging claw engages with the elongated hole, and the engaging claw projects The engaging member is elastically urged to engage with engaging holes formed at regular intervals in the vertical direction on the side surface of the rod, the operating lever is operated to move the operating rod upward, and the pin and the oblong elongated hole are operated. Since the relative position is changed, the engaging member is slid and disengaged from the engaging claw and the engaging hole, so that the height adjustment of the elevating top plate does not cause any practical inconvenience. It is not limited to the method that can be carried out in multiple stages and the support of the elevating table can be surely performed, and the cost can be significantly reduced because the mechanism is simple.

[Brief description of the drawings]

FIG. 1 is a side view of a wagon desk of the present invention.

FIG. 2 is an exploded perspective view showing a relationship among a side plate of a main body, a guide rod, and a support rod.

FIG. 3 is an exploded perspective view showing a stopper mechanism.

FIG. 4 is a partial cross-sectional view of the lifting device according to the present invention.

FIG. 5 is an enlarged cross-sectional view showing a main part of the present invention in an engagement state between an engagement claw and an engagement hole.

FIG. 6 is a partial cross-sectional view showing a connection structure between a lifting top plate and a support rod.

FIG. 7 is a partial longitudinal sectional view showing a relationship between an engagement member and a guide member.

FIG. 8 is an enlarged cross-sectional view of a state where the engagement is released from the state of FIG. 5;

9A and 9B show an upper slider, wherein FIG. 9A is a plan view and FIG. 9B is a cross-sectional view.

10A and 10B show a lower slider, where FIG. 10A is a bottom view and FIG. 10B is a cross-sectional view.

11 (a) is a side view, FIG. 11 (b) is a bottom view, and FIG. 11 (c) is a sectional view taken along line XX of FIG. 11 (a).

FIG. 12 is a partial cross-sectional view showing a state in which a mouse board is attached to a lower surface of a lifting top plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wagon desk 2 Main body 3 Fixed top plate 4 Elevating device 5 Elevating top plate 6 Side plate 7 Guide rod 8 Support rod 9 Pull out 10 Caster 11 Caster 12 Vertical groove 13 Stopper mechanism 14 Engagement hole 15 Fitting hole 16 Component member 16C 16D 16E Projecting piece 17 Constituent member 18 Operating lever 19 Operating rod 20 Guide member 21 Engaging member 22 Elastic urging means 23 Support shaft 24 Folding piece 25 Slit hole 26 Pin 27 Long hole 28 Caulking pin 29 Guiding recess 30 Regulatory protrusion REFERENCE SIGNS LIST 31 long hole 32 engaging claw 33 inclined long hole 34 fixing bracket 35 upper slider 36 lower slider 37 stopper 38 mounting bracket 39 cushioning member 40 mouse board 41 rail plate

Claims (1)

[Claims] 1. A lifting device for a wagon desk with a lifting top, comprising a lifting top supported in a height-adjustable manner above a fixed top of the wagon desk main body, wherein both side plates of the main body are provided. A hollow supporting rod having an upper end fixed to the elevating top plate is inserted vertically movably through a hollow guide rod vertically provided therein, and is disposed in the supporting rod body near the lower surface of the elevating top plate. An operating rod that only moves up and down in conjunction with the operation of the operating lever is vertically arranged, and an engaging claw protrudes from one side by a guide member fixed to the supporting rod at a lower portion within the supporting rod. An engaging member is provided so as to be slidable in the horizontal direction, a pin protruding from the operating rod is engaged with an oblong hole formed in the engaging member, and the engaging claw penetrates and projects through the supporting rod. Before engaging with the engaging holes formed at regular intervals in the vertical direction on the side of the rod The engaging member is elastically urged, the operating lever is operated by operating the operating lever, and the pin and the oblong hole change relative positions to slide the engaging member to engage the engaging claw. An elevating device for a wagon desk with an elevating top plate, wherein the engagement of the holes is released.