JPH10290716A - Top plate fixing structure for foldable table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lock at a using position from being detached even when large push-down force is applied to a conventional top plate in a foldable table capable of position-changing the top plate to a horizontal using position and an erected housing position. SOLUTION: For this top plate fixing structure of the foldable table, a lock pin 6 is provided on the side of a supporting leg 3, a lock plate 7 to be turned and engaged with the lock pin 6 is turned and energized in a locking direction and provided on the side of the top plate 2 and the lock plate 7 is provided with a first engaging edge 12a for fixing the using position of the top plate 2. The first engaging edge 12a is provided with a first circular arc part whose center is the turning supporting point 10 of the lock plate 7 and a second circular arc part to be gradually tightly engaged with the lock pin 5 accompanying the turning in an engaging direction of the lock plate 7. The first circular arc part is provided on the opening side of a groove part 12 and the second circular arc part is arranged on the back side of the groove part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a folding table suitable for a conference or a training session, for example, which can change its position between a horizontal use position and a storage position in which it is raised up. And a fixing structure of the top plate.

[0002]

2. Description of the Related Art Conventionally, a table of this type has been provided, for example, according to the application of the present applicant (Japanese Patent Application No. 7-288822). As shown in FIG. 10, the conventional folding table 30 includes a support leg 31 and the support leg 31.
A top plate 33 rotatably provided via a rotation shaft 32 and capable of changing its position between a horizontal use position and a storage position standing upright; and a top plate 33 for fixing the top plate 33 at each of the above positions. A lock plate 34 is provided. This lock plate 3
Reference numeral 4 is attached to a side portion of the top plate 33 via a support shaft 35 so as to be rotatable in a vertical direction, and is urged upward (in the engagement direction) by a torsion spring (not shown). On the other hand, a lock pin 3 with which the lock plate 34 engages is provided on the support leg 31 side.
6 are provided so as to protrude laterally.

The lock plate 34 has a first engagement edge 34a at the tip end of rotation and a second engagement edge 34b near the base of rotation.
The top plate 33 is positioned at a horizontal use position as shown in the figure, and the first engagement edge 34a of the lock plate 34 is engaged with the lock pin 36 from below, thereby forming the top plate. The use position of 33 is locked. The first engagement edge 34a intersects a circumference R1 centered on the rotation center (support shaft 35) of the lock plate 34 and gradually displaces outward (in a direction away from the rotation center). Is formed in the shape of an arc along. For this reason, as the lock plate 34 is rotated in the engagement direction by the urging force of the torsion spring or the manual operation, the first engagement edge 34a is brought into tighter engagement with the lock pin 36. 33 is firmly locked without play in the use position.

When the top plate 33 is stored in the storage position, the lock plate 34 is manually rotated once downward against the torsion spring so that the first engagement edge 34a is locked with respect to the lock pin 36. When the engagement is released, the top plate 33 is rotated upward in this state, and then the lock plate 34 is rotated in the engagement direction by the urging force of the torsion spring or manual operation.
The second engagement edge 34b is engaged with the lock pin 36,
Thereby, the top plate 33 is locked at the storage position.

[0005]

However, according to the above-described conventional folding table 30, when the top plate 33 is locked in the use position, as shown in the drawing,
A person pushes his hand at the tip (the left end in the figure with respect to the rotation fulcrum 32, that is, the end opposite to the seated occupant), and a downward pushing force P0 (the pushing force P0 is Board 33
Is applied, the lock plate 34 may come off.

That is, when a pressing force P0 is applied to the top plate 33, the first engaging edge 34a of the lock plate 34 is pressed against the lock pin 36 by a force P1 along a line connecting the support shaft 35 and the lock pin 36. . Lock plate 3
The first engaging edge 34a is formed not along the circumference R1 centered on the support shaft 35 as described above, but along the circumference R2 intersecting with the circumference R2 and displacing outward. Does not become a force along the normal direction of the circumference R2. For this reason,
When the first engagement edge 34a is pressed against the lock pin 36 by the force P1, the lock plate 34 exerts a force P to rotate downward (in the opposite engagement direction) as a reaction force from the lock pin 36.
2 acts, and when this force P2 exceeds the biasing force of the torsion spring,
As shown by the two-dot chain line in the figure, the lock plate 34 rotates in the anti-engagement direction, and as a result, the first engagement edge 34a comes off the lock pin 36.

As described above, when the conventional table 30 is fixed at the use position and a large depressing force P0 is applied to the top plate 33, the lock of the use position is released, and in this respect the usability is poor. was there.

Accordingly, an object of the present invention is to provide a top plate fixing structure of a folding table which can be used without any backlash at a use position and which does not easily come off the lock even when a large pressing force is applied. .

[0009]

For this purpose, the top plate fixing structure according to the first aspect is rotatably supported by a support leg and can be changed in position between a horizontal use position and a standing storage position. A fixing structure of the top plate in the use position in a folding table provided with a plate, wherein a lock pin is provided on one of the top plate or the support leg, and the other is rotated to engage with the lock pin. A lock plate is provided by being urged to rotate in an engagement direction, a first engagement edge for fixing a use position of the top plate is provided on the lock plate, and the lock plate is provided on the first engagement edge. A first arc portion centered on the rotation fulcrum and a second arc portion gradually and tightly engaged with the lock pin with the rotation of the lock plate in the engagement direction. One arc portion is disposed on the initial side of the engagement, and the second arc portion is disposed on the rear side of the engagement. And characterized in that a configuration.

According to this top plate fixing structure, the lock plate is rotated in the engagement direction while the top plate is located at the use position, and the first engagement edge is engaged with the lock pin. Then, the top plate is fixed at the use position. This fixed state is maintained more strongly as the lock plate is rotated more strongly in the engagement direction. This is because the second arc portion on the inner side in the engagement direction of the first engagement edge is provided so as to be tightly engaged with the lock pin as the lock plate is rotated in the engagement direction. With this, the top plate is firmly fixed without play in the use position.

[0011] In the state where the top plate is fixed in the use position in this manner, a downward pushing force (a force in a direction of erecting the top plate relative to the support leg) by, for example, clasping a hand with the top plate.
Is applied, this force acts in the direction of pressing the second arc portion against the lock pin and acts on the lock plate. Second
Since the arc portion is provided so as to be gradually and tightly engaged with the lock pin when the lock plate is rotated in the engagement direction as described above, the acting direction of the force acting on the lock plate (lock The line on the line connecting the center of rotation of the plate and the lock pin) does not coincide with the normal direction of the second arc portion. For this reason, when a force in the direction of pressing the second arc portion against the lock pin acts on the lock plate, a part of the repulsion force from the lock pin acts as a force for rotating the lock plate in the anti-engagement direction, Therefore, the lock plate once rotates in the anti-engaging direction.

However, when the lock plate rotates in the anti-engagement direction and the first arc portion on the engagement side of the first engagement edge is engaged with the lock pin, the first arc portion is engaged. Is an arc along the circumference centered on the rotation center of the lock plate, and its normal direction coincides with the direction of action of the force acting on the lock plate. For this reason, all the repulsive forces received by the lock plate from the lock pin are directed toward the rotation center of the lock plate, and no force is generated in the direction of rotating the lock plate. For this reason, even if a large pressing force is applied to the top plate, the lock plate does not come off from the lock pin, and thus the use position of the top plate is reliably maintained.

The top plate fixing structure according to the second aspect is the first aspect.
The top plate fixing structure according to any one of the preceding claims, further comprising: a second engagement edge for fixing a storage position of the top plate on the lock plate;
A third arc portion centered on the movable fulcrum and a fourth arc portion gradually engaged with the lock pin with the rotation of the lock plate in the engagement direction at the engagement edge. Provided,
It is characterized in that the third arc portion is arranged on the initial engagement side and the fourth arc portion is arranged on the engagement rear side.

According to this top plate fixing structure, the same operation and effect as described above can be obtained even when the top plate is fixed at the storage position. In order to fix the top plate from the use position to the storage position, first remove the lock plate from the lock pin in the use position, then raise the top plate to position the storage plate in the storage position. The top plate is fixed to the storage position by engaging the engagement edge with the lock pin. In this stored state, since the fourth arc portion is engaged with the lock pin, the top plate is firmly fixed to the stored position without play. Further, when a large force is applied to the top plate in the direction of rotating the top plate toward the use position while the top plate is in the storage position, the lock pin is engaged with the third arc portion to lock the top plate. The plate does not come off from the lock pin, so that the storage position of the top plate is reliably maintained.

According to a third aspect of the present invention, there is provided a top plate fixing structure.
Or the top plate fixing structure according to 2, wherein a flange portion is provided on the lock pin, and the flange portion restricts displacement of the lock plate in the plate thickness direction in the engaged state.

According to this top plate fixing structure, since the displacement of the lock plate in the plate thickness direction in the engaged state is restricted, even if the lock plate is displaced in the lateral direction due to vibration or impact applied to the folding table. It does not come off from the lock pin, so that the fixed state of the top plate can be reliably maintained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to FIGS. 6 and 7 show the folding table 1 according to the present embodiment. FIG. 6 shows a state in which the top plate 2 is fixed to a horizontal use position, and FIG. 7 shows a state in which the top plate 2 is fixed to a storage position. In FIG. 6, a person usually sits on the right side of the top plate 2. The table 1 of the present embodiment mainly includes a top plate 2 and a pair of left and right support legs 3 and 3 rotatably supported on respective lower surfaces thereof. As shown in the figure, the lower halves of each of the legs 3, 3 each have a bifurcated shape, and a total of four casters 3a to 3a are attached to the lower ends of the left and right legs 3,3.

A pair of left and right side frames 2a,
2a are attached in parallel with each other, and a plurality of shelf frames 2b to 2b are attached in parallel to each other at fixed intervals between both side frames 2a. On the other hand, a fixed plate 4 is attached to the upper end of the support leg 3, and a lock pin 5 is attached to the fixed plate 4.
Are protrudingly attached to the sides (front side in the figure). At the tip of the lock pin 5, a flange 5a is formed in an overhanging shape. The distance between the flange 5a and the fixing plate 4 is set to a size slightly larger than the thickness of a lock plate 7 described later.

The fixing plate 4 and the side frame 2a are connected via a support shaft 6, whereby the top plate 2 is supported on the support leg 3 so as to be rotatable up and down. The use position and the storage position of the top plate 2 are locked by a lock plate 7. The lock plate 7 includes a support shaft 10 on the side frame 2a.
Are supported so as to be rotatable up and down. Since the torsion spring 11 is interposed between the lock plate 7 and the side frame 2a, the lock plate 7 is urged in a counterclockwise direction (an engagement direction) in the figure.

At two positions in the longitudinal direction of the lock plate 7, grooves 12 and 13 are cut from side portions (upper side in the figure). A left side edge of the groove portion 12 on the rotation tip side in the figure is a first engagement edge 12a for abutting on the lock pin 5 to fix the top plate 2 at the use position, and is located in the middle in the longitudinal direction. The right side edge of the groove 13 in the drawing is
To fix the top plate 2 in the storage position by abutting engagement with the
An engagement edge 13a is provided.

The first engagement edge 12a is formed along two arc shapes as shown in FIG. The first arc portion 12b on the opening side of the groove portion 12 (the upper side in the figure, which corresponds to the initial engagement side described in the claims) has a rotation center of the lock plate 7, that is, an axis of the support shaft 10 as a center. It is formed along the circumference R1. This first arc portion 12b
The second arc portion 12c on the back side (the back side of the groove portion 12, which corresponds to the engagement back side described in the claims) following
A circumference R2 centered on a point different from the center of rotation of the lock plate 7, and intersects with the first circular arc portion 12b in the depth direction of the groove portion 12, and becomes the first portion as it reaches the depth portion of the groove portion 12. It is formed in an arc shape along the circumference R2 which gradually displaces inward with respect to the arc portion 12b.

When the lock plate 7 is rotated upward with the top plate 2 in the use position, the first engagement edge 12a
The position of the lock pin 5 or the size of each part is set so that the first circular arc portion 12b just contacts the lock pin 5. Therefore, when the lock plate 7 is further rotated upward from the state in which the lock pin 5 is in contact with and engaged with the first arc portion 12b, the lock pin 5 is then in abutment engagement with the second arc portion 12c. The second arc portion 12c is formed by the first arc portion 12
1b, the first engagement edge 12a (the second arc portion 12c) is gradually and tightly engaged with the lock pin 5, and thereby the top edge is displaced. The plate 2 is fixed at the use position without play.

On the other hand, the second engaging edge 13a is also formed along two circumferences R3 and R4 as shown in FIG. The third arc portion 13b on the opening side (upper side in the drawing) of the groove 13 is formed along the rotation center of the lock plate 7, that is, the circumference R3 around the axis of the support shaft 10. A fourth arcuate portion 13c on the far side following the third arcuate portion 13b intersects the third arcuate portion 13b in the middle of the depth direction of the groove and gradually displaces inward toward the depth side of the groove. It is formed in an arc shape along R4.

When the lock plate 7 is rotated upward with the top plate 2 in the storage position, the second engagement edge 13a
The position of the second engaging edge 13a, that is, the position of the third arc portion 13b with respect to the lock pin 5 is set so that the third arc portion 13b just contacts the lock pin 5. Therefore, the third
When the lock plate 7 is further rotated in the engagement direction (counterclockwise direction in the figure) from the state where the lock pin 5 is brought into contact with the arc portion 13b, the lock pin 5 then comes into contact with the fourth arc portion 13c. Engaged. Since the fourth arc portion 13c is displaced more gradually toward the inside of the groove portion 13 than the third arc portion 13b, the second engagement edge 13a (the fourth arc portion 13c) gradually moves with respect to the lock pin 5. The top plate 2 is fixed to the storage position without any play.

When the lock plate 7 is in contact with the lock pin 5 at the use position or the storage position of the top plate 2, the lock plate 7 enters between the flange 5 a of the lock pin 5 and the fixed plate 4, thereby The lateral movement of the lock plate 7 is suppressed.

According to the table 1 thus constructed, as shown in FIGS. 1 and 6, the top plate 2 is taken out to the use position, and the lock plate 7 is rotated in the engaging direction. If the second arc portion 12c of the engagement edge 12a is brought into contact with the lock pin 5, the top plate 2 is fixed to the use position without play.

In this use state, for example, the person
Considering a case where a downward pushing force P0 is applied by clapping a hand at the tip (an end opposite to the occupant) of the lock plate 7, the pushing force P0 is applied to the lock plate 7 via the support shaft 10. It acts as a force P1 for pressing the one engagement edge 12a against the lock pin 5. On the other hand, in this use state, the first engagement edge 12
The second arc portion 12 a of FIG. Since the second arc portion 12c is formed along the circumference R2 which does not center on the support shaft 10, the pressing force P
The reaction force received from the lock pin 5 by the first
Therefore, a part of the reaction force received from the lock pin 5 becomes a component force (rotational force P2) in the direction for rotating the lock plate 7 in the anti-engagement direction. Acts on the second arc portion 12c.

Therefore, when the rotational force P2 exceeds the biasing force of the torsion spring 11, the lock plate 7 rotates in the anti-engaging direction, and as a result, the lock pin 5 relatively moves toward the opening side of the groove 12, and A transition is made from the abutting engagement state with the second arc portion 12c to the abutting engagement state with the first arc portion 12b. Since the first arc portion 12b is formed along the circumference R1 about the center of rotation of the lock plate 7, the reaction force received from the lock pin 5 by the pressing force P1 is normal to the first arc portion 12b. Therefore, a force for rotating the lock plate 7 in the anti-engagement direction is not generated. From this, when the lock plate 7 rotates by a predetermined angle in the anti-engagement direction and the lock pin 5 comes into contact with the second arc portion 12c, the lock plate 7 rotates in the anti-engagement direction. The movement stops, so that the contact state of the first engagement edge 12a with the lock pin 5 is maintained, and thus the top plate 2
The fixed state in the use position of is maintained.

Next, when the lock plate 7 is manually rotated in the anti-engagement direction to release the contact state of the lock pin 5 with the first engagement edge 12a, the top plate 2 at the use position is used. The fixing can be released, so that the top plate 2 can be rotated in the upright direction. In the state where the top plate 2 has been rotated to the storage state as shown in FIGS. 2 and 7, the lock plate 7 is again rotated in the engagement direction, whereby the second engagement edge 13a contacts the lock pin 5. Contact engagement. By strongly rotating the lock plate 7 in the engagement direction, the lock pin 5 is brought into tighter contact with the fourth arc portion 13c, whereby the top plate 2 is fixed to the storage position without play.

In this stored state, considering a case where a pressing force P3 is applied to the top plate 2 to the use position side, the pressing force P3 is transmitted via the support shaft 10 to the second engaging edge 1.
3a acts as a force R4 for pressing the lock pin 5 against the lock pin 5. In this stored state, the fourth arc portion 13c of the second engagement edge 13a is engaged with the lock pin 5. This fourth
Since the arc portion 13c is formed along the circumference R4 not centering on the support shaft 10, the reaction force received from the lock pin 5 by the pressing force P4 is equal to the force along the normal direction of the fourth arc portion 13c. Therefore, part of the reaction force received from the lock pin 5 becomes a component (rotational force P5) in the direction of rotating the lock plate 7 in the anti-engagement direction, so that the fourth arc portion 13c is formed.
Act on.

Therefore, when the rotational force P5 exceeds the biasing force of the torsion spring 11, the lock plate 7 rotates in the anti-engaging direction, and as a result, the lock pin 5 relatively moves to the opening side of the groove 13, and The state is shifted from the contact engagement state with the fourth arc portion 13c to the contact engagement state with the third arc portion 13b. Since the third arc portion 13b is formed along the circumference R3 about the center of rotation of the lock plate 7, the reaction force received from the lock pin 5 by the pressing force P4 is normal to the third arc portion 13b. Therefore, a force for rotating the lock plate 7 in the anti-engagement direction is not generated. From this, when the lock plate 7 rotates by a predetermined angle in the anti-engagement direction and the lock pin 5 comes into contact with the third arc portion 13c, the lock plate 7 rotates in the anti-engagement direction. The movement stops, so that the abutting engagement state of the second engagement edge 13a with the lock pin 5 is maintained.
The fixed state in the storage position is maintained.

As described above, according to the top plate fixing structure of this embodiment, the pressing force P0 is applied to the top plate 2 fixed at the use position, or the top plate 2 fixed at the storage position is pressed down. Even when the force P3 is applied, the lock plate 34 does not come off from the lock pin 36 as in the prior art, and the contact engagement state of the lock plate 7 with the lock pin 5 is reliably maintained, Thereby, the top plate 2 can be securely fixed to the use position or the storage position.

According to the top plate fixing structure of the present embodiment, since the lock pin 5 is provided with the flange 5a,
The displacement of the lock plate 7 in the plate thickness direction in the contact engagement state is restricted. According to this, in a state where the top plate 2 is fixed to the use position or the storage position, the table 1
For example, even when vibration or impact is applied in the lateral direction (the surface direction of the top plate 2), the lock plate 7 is reliably prevented from moving in the plate thickness direction and coming off the lock pin 5, so that the top plate 2 The use position or the storage position of is surely maintained. It should be noted that the locking plate 5 can be prevented from dropping off the lock pin 5 by providing the lock pin 5 sufficiently long instead of providing the flange portion 5a as described above. It is not preferable because the size of the protrusion in the direction increases. According to the flange portion 5a of this embodiment, the top plate 2 can be securely fixed by minimizing the size of the protrusion to the side.

Next, a second embodiment of the present invention will be described.
FIG. 8 shows a fixed state of the top plate 2 at the use position, and FIG.
Indicates a fixed state in which the top plate 2 is stored. Points that do not need to be changed from those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The top plate fixing structure of the first embodiment has a configuration in which the lock plate 7 is directly rotated, whereas the second embodiment has a configuration in which the lock plate 21 is indirectly rotated by a rotation operation of the lock lever 20. It has become.

A fixing plate 22 is attached to the upper part of the support leg 3, and the top plate 2 is supported via a support shaft 23 of the fixing plate 22 so as to be rotatable up and down. A lock lever 20 is mounted on the support shaft 23 so as to be rotatable up and down.
However, the lock lever 20 is rotatable independently of the top plate 2. A lock plate 21 is connected to a rear portion of the lock lever 20 via a support shaft 24, and the lock plate 21 is rotatably attached to the side frame 2 a of the top plate 2 via a support shaft 25. This lock plate 21 is urged to rotate upward in the figure by a torsion spring 26 as in the first embodiment. For this reason, when the lock lever 20 is rotated upward in the figure against the torsion spring 26, the lock plate 21 is rotated in the clockwise direction (anti-engagement direction) around the support shaft 25, and the lock lever 21 is rotated. When the rotation of the lock plate 20 is stopped, the lock plate 21 is returned in the counterclockwise direction (the engagement direction) by the urging force of the torsion spring 26, and the lock lever 20 rotates clockwise in the drawing.

As in the first embodiment, grooves 30 and 31 are cut from the upper edge of the lock plate 21,
The left side of the groove 30 on the front side of the rotation is the first engagement edge 30a for fixing the use position, and the right side of the groove 31 on the base of the rotation is the second engagement for fixing the storage position. The edge 31a is set. Although not shown, the first and second engagement edges 3
Reference numerals 0a and 31a each include two arc portions. The arc on the opening side of the groove is formed along the circumference around the rotation center (support shaft 25) of the lock plate 21, and the arc on the back side of the groove intersects the arc on the opening side, and It is formed along a circumference that is displaced inward toward the side.

A lock pin 27 is provided on the fixed plate 22 so as to protrude to the side. When the top plate 2 is used, the first engagement edge 30a is brought into abutment engagement with the lock pin 27. The lock position is fixed by the lock pin 27.
Is fixed by bringing the second engagement edge 31a into abutment engagement. This is also the same as in the first embodiment.

According to the top plate fixing structure of the second embodiment configured as described above, when the top plate 2 is located at the use position and the rotation operation of the lock lever 20 is stopped as shown in FIG. 21 rotates in the engagement direction (counterclockwise direction in the figure), and the top plate 2 is fixed at the use position by abuttingly engaging the lock pin 27 with the first engagement edge 30a. On the other hand, when the lock lever 20 is rotated upward in the figure by a manual operation, the lock plate 21 rotates in the anti-engagement direction about the support shaft 25, whereby the lock pin 27 with respect to the first engagement edge 30a is rotated. The contact engagement state is released.

When the first engagement edge 30a is released from the abutting engagement with the lock pin 27, the top plate 2 is rotatable about the support shaft 23 in the upright direction. When the rotation operation of the lock lever 20 which has been operated is stopped in a state where the top plate 2 is rotated to the storage position, the lock plate 21 is rotated in the engagement direction by the torsion spring 26, whereby the second engagement The lock pin 27 is brought into contact with the mating edge 31a, and the top plate 2
Is fixed in the storage position.

When the top plate 2 is fixed to the use position or the storage position in this manner, even if a force in the rotating direction is applied to the top plate 2, the circular arc portions on the groove opening side with respect to the lock pins 27 are respectively locked plates. 21 rotation center (support shaft 2
Since the lock plate 21 is formed along the circumference centered at 5), the lock plate 21 does not come into contact with the lock pin 27 so as not to be disengaged. Therefore, the use position of the top plate 2 as in the first embodiment. Alternatively, the fixed state at the storage position is reliably maintained.

In the case of the second embodiment as well, by providing the lock pin 27 with a flange, the lock plate 2
1 can be restricted in the thickness direction, so that even if a lateral vibration or impact is applied to the folding table as in the first embodiment, the lock plate 21 can be prevented.
Is not disengaged from the lock pin 27, so that the top plate 2
Is reliably maintained.

The two embodiments described above can be implemented with various modifications. For example, the first and second engagement edges 12a, 13a (30a, 31a)
Although the configuration provided on one side of the grooves 12, 13 (30, 31) has been exemplified, the grooves need not necessarily be formed in order to provide each engagement edge.

The torsion springs 11 and 26 may be replaced by tension springs. The tension spring is, for example, a lock plate 7.
What is necessary is just to mount | wear between the and the support shaft 6 like a bridge.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, and is a side view of a folding table in a state where a top plate is fixed at a use position.

FIG. 2 is a side view of the folding table in a state where a top plate is fixed to a storage position.

FIG. 3 is an exploded perspective view of the vicinity of a top support.

FIG. 4 is a detailed view of an IV section of FIG. 1, and is a side view showing first and second arc portions of a first engagement edge.

FIG. 5 is a detailed view of a portion V in FIG. 2, showing a third portion of the second engagement edge;
It is a side view which shows a 4th circular arc part.

FIG. 6 is an overall side view of the folding table in a state where the top plate is fixed at a use position.

FIG. 7 is an overall side view of the folding table in a state where the top plate is fixed to the storage position.

FIG. 8 is a view showing a second embodiment of the present invention, and is a side view of a folding table in a state where a top plate is fixed at a use position.

FIG. 9 is a view showing a second embodiment of the present invention;
It is a side view of the folding table in the state where the top board was fixed to a storage position.

FIG. 10 is a side view of a folding table provided with a conventional top plate fixing structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Folding table 2 ... Top plate 3 ... Leg 4 ... Fixing plate 5 ... Lock pin, 5a ... Flange 7 ... Lock plate 11 ... Torsion spring 12a ... 1st engagement edge, 12b ... 1st circular part, 12c ... Second arc portion 13a: second engagement edge, 13b: third arc portion, 13c: fourth arc portion R1, R3: circumference around the center of rotation of lock plate R2, R4: rotation of lock plate A circumference not centered on the center P0: a pressing force against the top plate at the use position P1: a pressing force of the first engagement edge against the lock pin P2: a reaction force received from the lock pin, and a force for rotating the lock plate P3 ... Depressing force against the top plate at the storage position P4 ... Pressing force of the second engaging edge against the lock pin P5 ... Reaction force received from the lock pin and force to rotate the lock plate 20 ... Lock lever 21 The lock plate

Claims (3)

[Claims] 1. A fixing structure of a folding table having a top plate rotatably supported by a support leg and capable of changing a position between a horizontal use position and an upright storage position in the use position. A lock pin is provided on one of the top plate or the support leg, and a lock plate that is rotated to be engaged with the lock pin is provided on the other by rotating and urging in the engagement direction. A first engagement edge for fixing a use position of the top plate, a first arc portion centered on a rotation fulcrum of the lock plate on the first engagement edge, A second arc portion that is gradually and tightly engaged with the lock pin with the rotation in the engagement direction is provided, and the first arc portion is engaged on the initial side and the second arc portion is engaged. Top plate of folding table, characterized in that it is arranged on the back side Constant structure. 2. The top plate fixing structure according to claim 1, wherein
The lock plate has a second engagement edge for fixing a storage position of the top plate, and the second engagement edge has a third arc portion centered on the movable fulcrum, and an engagement direction of the lock plate. A fourth arc portion that is gradually and tightly engaged with the lock pin in accordance with the rotation of the third arc portion, the third arc portion is on the initial engagement side, and the fourth arc portion is on the engagement rear side. A top plate fixing structure for a folding table, wherein the top plate is fixed. 3. The top plate fixing structure according to claim 1, wherein a flange portion is provided on the lock pin, and the displacement of the lock plate in the plate thickness direction in the engaged state is regulated by the flange portion. A top plate fixing structure for a folding table, characterized in that: