Brace locking device

Abstract

The present invention provides a locking device for locking a retractable brace in a retracted state. [Solution] A locking device (16) is constructed by a locking means (17) and a locked means (18) provided on the mutually adjacent first opposing part (14) and second opposing part (15), which are close together when the brace is in a contracted state and separated when it is in an extended state. The locking means (17) rotates between a closed position (Q) where the rotation angle is closed so as to be aligned with the first opposing part (14) and an open position (R) where the rotation angle is opened so as to be separated from the first opposing part (14). The locking means (17) is configured to lock when rotated to the closed position (Q) with the first opposing part (14) and the second opposing part (15) in close proximity, and to unlock when rotated from the closed position (Q) toward the open position (R).

Description

Technical Field

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[0001] The present invention relates to a locking device for locking a telescopic brace in a contracted state, particularly to a locking device for a brace provided on a folding workbench.

Background Art

[0002] Conventionally, for example, there has been provided a workbench that can be changed in posture between a deployed posture in which left and right top plates supported by left and right column bases are positioned on the same plane, and a folded posture in which the left and right columns are moved in a direction approaching each other and the left and right top plates are in a mountain-folded state.

[0003] Such a workbench is configured such that a brace is disposed between the column base and the top plate, and both ends of the brace are pivotally connected to the column base and the top plate rotatably, respectively, so as to support the deployed top plate on the column.

[0004] ​​​​​​​​​​​​​​​​​​​​​​​​​

[0007] As described above, the extendable brace extends when the workbench is folded and contracts when it is unfolded, supporting the tabletop to the column base in this contracted state. When the brace is in the contracted state, the locking device locks the pair of brace members so that they cannot slide against each other, allowing the brace to perform its intended support function.

[0008] Incidentally, in the case of the conventional technology, with respect to a brace constructed by slidably inserting one brace material (outer tube) into the other brace material (inner tube), the locking device is configured to lock both brace materials so that they cannot slide by screwing a bolt with a knob into the outside of one brace material (outer tube) and fastening the tip of the bolt to the surface of the other brace material (inner tube).

[0009] Therefore, when locking the brace so that it cannot be extended or retracted, the worker must rotate the knob clockwise with their fingers to advance the bolt, and conversely, when unlocking it, they must rotate the knob counterclockwise with their fingers to retract the bolt, which presents a problem as it forces them to perform such a cumbersome task.

[0010] The present invention aims to solve these problems and provide a locking device configured to reduce the work required for locking and unlocking. [Means for solving the problem]

[0011] Therefore, the means configured in the present invention is a brace configured to be expandable and contractible between a contracted state and an extended state by sliding a first brace member and a second brace member toward each other in the axial direction, wherein the first brace member and the second brace member are provided with a first opposing part and a second opposing part that are close together when in the contracted state and separated when in the extended state, and a locking device is configured between the two opposing parts, wherein the locking device is configured with a locking means that is rotatably provided via a pivot that intersects the first opposing part and has a locking part at its tip, and a locking means provided on the second opposing part and has a locking part, The locking means rotates between a closed position, where the rotation angle is closed so as to be aligned with the first opposing portion, and an open position, where the rotation angle is opened so as to be separated from the first opposing portion. When the locking means is rotated to the closed position toward the locked means with the first opposing portion and the second opposing portion in close proximity to each other, the locking portion engages with the locked means, thereby locking the first brace material and the second brace material so as not to slide. When the locking means is rotated toward the open position away from the locked means, the locking portion disengages from the locked means, thereby unlocking the first brace material and the second brace material so as to be able to slide.

[0012] In this case, it is preferable that the locking device is provided with a biasing means that biases the locking means toward the direction that engages the locking portion with the locked portion when the locking means is rotated to the closed position to engage the locking portion with the locked portion.

[0013] In a preferred embodiment of the present invention, the locking device is configured such that, when the first opposing part and the second opposing part are separated, the locking means and the locking means are each provided with a fixed cam and a movable cam, respectively, and when the locking means is rotated to the closed position, the first opposing part and the second opposing part are moved to be closer to each other, the movable cam (24b) moves along the fixed cam (26b), causing the locking means to rotate toward the open position against the biasing means, and when the locking means overcomes the locking means, the biasing means rotates the locking means to the closed position.

[0014] In an embodiment of the present invention, a workbench is capable of changing its orientation from an unfolded position, in which the left and right top plates supported by the left and right legs are positioned on the same plane, to a folded position, in which the left and right support columns are moved in a direction toward each other and the left and right top plates are folded in a mountain-fold state. Preferably, the extendable brace is disposed between the legs and the top plates, and both ends of the brace are pivotally connected to the legs and the top plates, respectively, so as to be possible when changing the orientation of the workbench from the unfolded position to the folded position, the brace extends and moves toward and overlaps with the top plates. In this case, the locking means of the locking device is configured to move toward the top plates when rotated from the closed position to the open position, and when the orientation of the workbench is changed from the unfolded position to the folded position with the locking means rotated toward the closed position by the pushing of the top plates. [Effects of the Invention]

[0015] According to the present invention, in a retractable brace that enables contraction and extension by sliding a first brace material and a second brace material toward each other in the axial direction, a locking device is provided that prevents extension by locking the brace in the contracted state and enables extension by unlocking it, thereby reducing the work required when locking and unlocking. [Brief explanation of the drawing]

[0016] [Figure 1] The diagram illustrates a workbench equipped with the brace of the present invention, where (A) is a perspective view of the workbench in its extended position and (B) is a perspective view of the workbench in its folded position. [Figure 2] Regarding the brace installed on the workbench, (A) is a front view showing the workbench in its deployed position, (B) is a perspective view showing the locking device in the locked state, and (C) is a perspective view showing the locking device in the unlocked state. [Figure 3] Regarding the brace installed on the workbench, (A) is a front view showing the state when the workbench is changing from an unfolded position to a folded position, and (B) is a front view showing the action of the locking mechanism of the locking device being rotated from the open position to the closed position by the top plate of the workbench. [Figure 4] Regarding the brace installed on the workbench, (A) is a front view showing the workbench in its folded position, and (B) is a front view showing the brace and locking device. [Figure 5] Regarding embodiments of the brace and locking device, (A) is a perspective view showing the disassembled state, and (B) is a perspective view showing the opposing portion of the brace material on the side where the locking means is provided. [Figure 6] Regarding embodiments of the brace and locking device, (A) is a perspective view showing the first brace material and the second brace material separated, and (B) is a cross-sectional view showing the opposing portion of the brace material on the side where the locking means is provided. [Figure 7] Regarding embodiments of the brace and locking device, (A) is a perspective view showing the locking device in a locked state, and (B) is a cross-sectional view showing the locking device in an unlocked state. [Figure 8]Regarding the operation of the locking device, (A) is a front view showing the state when the locking means is rotated to the closed position, (B) is an explanatory view of the operation of the biasing means when the locking means is in the closed position, (C) is a front view showing the state of the intermediate position when the locking means is rotated from the closed position towards the open position, (D) is an explanatory view of the operation of the biasing means when the locking means is in the intermediate position, (E) is a front view showing the state when the locking means is rotated to the open position, and (F) is an explanatory view of the operation of the biasing means when the locking means is in the open position. [Figure 9] Regarding the operation of the locking device, (A) is a front view showing the state in which a pair of brace members slide from the extended state towards the contracted state when the locking means is in the closed position, (B) is an explanatory view of the operation of the fixed cam portion and the moving cam portion constituting the cam means, (C) is a front view showing the state in which the locking means is rotated from the closed position towards the open position by the cam means, and (D) is a front view showing the state in which the locking means is rotated to the closed position and locked by the biasing means after overcoming the locked means. [Figure 10] Another embodiment of the locking device is shown, where (A) is a perspective view showing the disassembled state of the locking means and the brace members, and (B) is a perspective view showing the opposing portion of the brace member on the side where the locking means is provided. [Figure 11] Regarding another embodiment, (A) is a perspective view showing the state in which the brace is locked by the locking device, and (B) is a cross-sectional view showing the opposing portion of the brace member on the side where the locking means is provided. [Figure 12] Regarding the operation of the locking device in another embodiment, (A) is a front view showing the state immediately before locking by rotating the locking means towards the closed position, (B) is an explanatory view of the operation of the biasing means immediately before locking, (C) is a front view showing the state locked by the locking means, and (D) is an explanatory view of the operation of the biasing means in the locked state.

Embodiments for Carrying out the Invention

[0017] The preferred embodiments of the present invention will be described in detail based on the following drawings.

[0018] (Configuration of the workbench) Figures 1 to 5 show an example of a workbench and an embodiment of a brace installed on the workbench.

[0019] The workbench consists of a top plate 2 supported by a pair of legs 1A and 1B that are spaced apart in the X direction with respect to the orthogonal X and Y directions on a plane, and is used for working at heights with the top plate 2 as the work platform.

[0020] The top plate body 2 is designed to allow for orientation changes between an unfolded position P1 in which a pair of top plates 2A and 2B, divided in the X direction, are positioned on the same plane, and a folded position P2 in which they are positioned in a mountain-fold shape. For this reason, the opposing ends of the top plates 2A and 2B are connected by a connecting means 3 that can rotate around a horizontal axis.

[0021] The leg bodies 1A and 1B each form a rigid structure by connecting a pair of column bases 4, 4 spaced apart in the Y direction with a horizontal bar 5, and the upper ends of each column base 4 are pivotally connected to the lower side near the four corners of the top plate body 2 so as to be rotatable around a horizontal axis.

[0022] To enable the aforementioned posture changes, a push-up rod 6 hanging down from the connecting means 3, an extension rod 7 slidably extending downward from the rod 6, a push-up link 8 connecting the push-up rod 6 to the leg bodies 1A and 1B, and a push-down link 9 connecting the extension rod 7 to the underside of the opposing ends of the top plates 2A and 2B are provided.

[0023] Furthermore, a caster 10 is provided at the lower end of the column base 4.

[0024] The workbench configured in this way can be positioned between the unfolded position P1 shown in Figures 1(A) and 2(A) and the folded position P2 shown in Figures 1(B) and 4(A). An intermediate position PM between the unfolded position P and the folded position P2 is shown in Figure 3(A).

[0025] When the legs 1A and 1B are moved in the X direction from the deployed position P1 shown in Figure 2(A) so that they are close to each other, the top plates 2A and 2B are tilted in the mountain-fold direction via the connecting means 3, as shown in the intermediate position PM shown in Figure 3(A). At this time, the push-up link 8 causes the push-up rod 6 to move upward, lifting the connecting means 3, and the push-down link 9 causes the extension rod 7 to move downward. As a result, the movement of the legs 1A and 1B and the tilting of the top plates 2A and 2B are performed synchronously in a mutually connected state. Then, as shown in Figure 4(A), when the folding position P2 is achieved, the top plates 2A and 2B are arranged parallel to each other in a nearly vertical position on both sides of the connecting means 3, and the legs 1A and 1B are positioned between them, nearly overlapping and arranged parallel, enabling a compact folding position P2.

[0026] (Brace configuration) In the above workbench, braces 11 are provided between the leg body 1A and the top plate 2A, and between the leg body 1B and the top plate 2B. In the workbench shown in the figure, with respect to the leg body 1A and top plate 2A on the left side of the figure, two braces 11 are provided between the middle part of a pair of column legs 4, 4 arranged in the Y direction (directly above the push-up link 8) and the vicinity of the push-up rod 6 on the underside of the top plate 2A. Similarly, with respect to the leg body 1B and top plate 2B on the right side of the figure, two braces 11 are provided between the middle part of a pair of column legs 4, 4 arranged in the Y direction (directly above the push-up link 8) and the vicinity of the push-up rod 6 on the underside of the top plate 2B.

[0027] The four braces 11 each have the same configuration, and both ends are pivotally connected to the column base 4 and the top plate 2A (2B), allowing them to be extended and retracted.

[0028] Therefore, the brace 11 is configured to be expandable and contractible between a contracted state and an extended state by combining a first brace member 12 and a second brace member 13 so that they can slide against each other in the axial direction. The first brace member 12 and the second brace member 13 each have a first opposing part 14 and a second opposing part 14 that are close together when in the contracted state and separate when in the extended state, and a locking device 16 is formed between the two opposing parts 14 and 15.

[0029] In the embodiments shown in Figures 1 to 4, the tail end of the first brace member 12 is pivotally connected to the top plate 2A (2B), and the tail end of the second brace member 13 is pivotally connected to the column base 4. However, they may be arranged in the opposite direction. That is, the tail end of the first brace member 12 may be pivotally connected to the column base 4, and the tail end of the second brace member 13 may be pivotally connected to the top plate 2A (2B).

[0030] (Details of the brace) Figures 5 to 9 show in detail embodiments of the brace 11.

[0031] The first brace member 12 is composed of an outer member 12a formed from a pipe extruded from metal, and an inner member 12b that is inserted into and fixed to the outer member 12a and extends along the coaxial line. In contrast, the second brace member 13 is formed from the same pipe as the outer member 12a of the first brace member 12. Therefore, by slidably inserting the inner member 12b of the first brace member 12 into the pipe of the second brace member 13, an expandable and retractable brace 11 is constructed.

[0032] In this case, the outer member 12a of the first brace member 12 and the second brace member 13 form a first opposing portion 14 and a second opposing portion 15, respectively, by their mutually opposing ends. When the brace 11 is in a contracted state, the first opposing portion 14 and the second opposing portion 15 come into contact with each other or are close with a gap between them. Hereafter, the term "close" will be used in the explanation, but please understand that this includes contact.

[0033] Therefore, when the brace 11 is in a retracted state, a locking device 16 is provided between the first opposing portion 14 and the second opposing portion 15, which are in close proximity to each other, and the locking device 16 consists of a locking means 17 that is rotatably provided on the first opposing portion 14 and a locking means 18 provided on the second opposing portion 15.

[0034] Incidentally, in the illustrated embodiment, the end of the outer member 12a of the first brace member 12 is designated as the first opposing portion 14, and the end of the second brace member 13 is designated as the second opposing portion 15. However, the configuration may also be such that the first opposing portion 14 and the second opposing portion 15 are swapped. That is, the end of the second brace member 13 may be designated as the first opposing portion and a locking means 17 may be provided, and the end of the outer member 12a of the first brace member 12 may be designated as the second opposing portion 15 and a locking means 18 may be provided.

[0035] (Locking device) The locking mechanism 17 is rotatably supported via a pivot 19 that intersects the first opposing portion 14 and comprises an opening / closing member 20 that extends beyond the tip of the first opposing portion 14. The opening / closing member 20 includes a pair of arm portions 20a, 20a facing both side walls of the first opposing portion 14 and an operating portion 20b integrally straddling both arm portions 20a, 20a. Thus, by pivoting the tail ends of the arm portions 20a, 20a with the pivot 19, the opening / closing member 20 is rotated between a closed position Q (see Figure 8(A)) where the rotation angle is closed so that the operating portion 20b is along the upper wall of the first opposing portion 14, and an open position R (see Figure 8(E)) where the rotation angle is opened so that it moves away from the upper wall of the first opposing portion 14.

[0036] In the illustrated embodiment, the pivot 19 not only functions as a support shaft for the locking means 18, but is also located at the first opposing portion 14 of the first brace member 12 and functions as a fastener that fixes the insertion portions of the outer member 12a and the inner member 12b.

[0037] As shown in Figure 6(B), the pivot 19 is composed of a pair of bolts 21, 21 that penetrate both side walls of the outer material 12a constituting the first opposing portion 14. In this case, the threaded shaft portion 21a of the bolts 21 is screwed into nuts 22, 22 that are inserted through the side walls and fixed by crimping or the like. The side walls of the inner material 12b are then clamped together by the threaded shaft portions 21a, 21a of the pair of bolts 21, 21, thereby fixing the outer material 12a and the inner material 12b together as one unit.

[0038] The bolt 21 has a support shaft portion 21b that protrudes from the side wall of the outer material 12a and a flange portion 21c at the shaft end. The support shaft portion 21b is inserted through a support hole 20c provided at the tail end of the arm portion 20a of the opening / closing member 20 that constitutes the locking means 17, thereby pivotally supporting the opening / closing member 20.

[0039] The opening / closing member 20 constituting the locking means 18 has a claw portion 23 at the tip of an arm portion 20a that protrudes from the first opposing portion 14 when in the closed position Q, and the claw portion 23 is provided with a locking portion 24a and a movable cam portion 24b.

[0040] In contrast, the locking means 18 is configured by fixing a U-shaped fixing member to the second opposing portion 15, and providing tongue pieces 25 that protrude from both side walls of the second opposing portion 15 to the fixing member, with a locking portion 26a and a fixing cam portion 26b provided on the tongue pieces 25.

[0041] (Opening and closing action of the locking mechanism) When the first brace member 12 and the second brace member 13 are contracted and the first opposing portion 14 and the second opposing portion 15 are brought close together, the opening / closing member 20 of the locking means 17 is rotated from the open position R to the closed position Q. The locking portion 24a provided on the claw portion 23 engages with the locking portion 26a provided on the tongue piece 25 of the locked means 18, locking both brace members 12 and 13 so that they cannot be extended. From this state, when the opening / closing member 20 is rotated towards the open position R, the locking portion 24a disengages from the locking portion 26a, unlocking both brace members 12 and 13 so that they can be extended. In the illustrated embodiment, a knob portion 20d is provided on the operating portion 20b to facilitate the opening and closing operation of the opening / closing member 20.

[0042] When the opening / closing member 20 of the locking means 17 is rotated to the closed position Q to lock it, a biasing means 27 is provided to bias the opening / closing member 20 in the direction that engages the locking portion 24a with the locked portion 26a. In the embodiments shown in Figures 1 to 9, the biasing direction of the biasing means 27, which is the "direction that engages the locking portion 24a with the locked portion 26a," is the rotational direction around the pivot 19.

[0043] In this embodiment, the biasing means 27 is composed of a tensioning means 28 such as a coil spring that generates a biasing force in the tensile direction, and the tensioning means 28 is stretched between a stopper 29a provided on the opening / closing member 20 and a stopper 29b provided on the outer member 12a of the first brace member 12.

[0044] In this case, the tensioning direction of the tensioning means 28 is represented as a line L that defines the biasing direction by the line connecting the stoppers 29a and 29b, and the line L is configured to be positioned as follows with respect to the center C of the pivot 19, which is the rotation center of the opening / closing member 20. (1) As shown in Figures 8(A) and 8(B), when the opening / closing member 20 is rotated to the closed position Q, the line L is positioned to pass below the center C of the pivot 19. Therefore, the opening / closing member 20 is biased in the downward rotation direction and is held in the closed position Q with the operating part 20b resting on the first opposing part 14 or the second opposing part 15. (2) As shown in Figures 8(C) and 8(D), when the opening / closing member 20 is rotated slightly from the closed position Q to the open position R, and the locking portion 24a is in a position where it has disengaged from the locked portion 26a, the line L is still positioned to pass below the center C of the pivot 19 and is acting as a biasing force in the downward rotation direction. Therefore, when the first brace material 12 and the second brace material 13 are moved slightly in the extension direction, as shown in the figure, the claw portion 23 of the opening / closing member 20 is elastically in contact with the upper edge of the tongue piece 25, and the opening / closing member 20 is held in this position. (3) As shown in Figures 8(E) and 8(F), when the opening / closing member 20 is rotated toward the open position R such that the claw portion 23 moves away above the tongue piece 25, the line L is positioned to pass above the center C of the pivot 19, biasing the opening / closing member 20 in the upward rotational direction. Therefore, the opening / closing member 20 is elastically biased toward the open position R. The opening / closing member 20 is held in the open position R by the stopper 20e provided at the tail end coming into contact with the second brace member 13.

[0045] (Lock and unlock) In the workbench in the unfolded position P1 shown in Figure 2(A), the brace 11 is in a contracted state with the first brace member 12 and the second brace member 13 retracted, as shown in Figure 2(B), and the opening / closing member 20 is rotated to the closed position Q and locked by the locking device 16 so that it cannot be extended. Therefore, when changing the position of the workbench to the folded position P2 shown in Figure 4(A), the worker rotates the opening / closing member 20 to the open position R and unlocks the locking device 16, as shown in Figure 2(C). At this time, the rotation direction of the opening / closing member 20 is configured such that when it rotates from the closed position Q to the open position R, the opening / closing member 20 moves closer to the underside of the top plate 2A (2B), and is held in the rotated position Q by the biasing means 27 as described above.

[0046] As described above, the movement of the workbench when changing its position from the unfolded position P1 to the folded position P2 is as shown in Figure 3(A). When the intermediate position PM is adopted, the tilting top plate 2A (2B) and the extending brace 11 approach each other. Then, as shown in Figure 4(A), when the folded position P2 is adopted, they are superimposed almost parallel to each other.

[0047] Therefore, as shown in Figures 3(B) and 4(B), the opening / closing member 20, which is in the open position Q, is pushed by the tilting top plate 2A (2B) and rotated to automatically return to the closed position R. Furthermore, as explained based on Figures 8(C) and 8(D), when the line L moves from the upper side to the lower side of the pivot 19's center C, the direction of the biasing force received by the tensioning means 28 switches from the upward rotation direction of the opening / closing member 20 to the downward rotation direction. Consequently, after the opening / closing member 20 is pushed by the top plate 2A (2B) to the position where the biasing direction switches, it rotates to the closed position Q on its own by receiving the biasing force.

[0048] As mentioned above, when the workbench is in the folded position P2, the locking device 16 of the brace 11 holds the opening / closing member 20 in the closed position Q. Therefore, when changing the position to the opposite of the above, that is, when changing the position of the workbench from the folded position P2 to the unfolded position P1, the first brace member 12 and the second brace member 13 are moved from the extended state to the contracted state, and the first opposing part 14 and the second opposing part 15 come into close proximity. At this time, the opening / closing member 20 of the locking device 16 is held in the closed position Q, so in order to lock it, the worker must first rotate the opening / closing member 20 toward the open position R, and when the first opposing part 14 and the second opposing part 15 come into close proximity, rotate the opening / closing member 20 toward the closed position Q, and engage the locking part 24a with the locked part 26a.

[0049] To automate this action, the locking device 16 of this embodiment is provided with a fixed cam portion 26b on the tongue piece 25 and a movable cam portion 24b on the claw portion 23. As shown in Figure 9, the movable cam portion 24b and the fixed cam portion 26b are formed on the mutually opposing edges of the claw portion 23 and the tongue piece 25 when the first opposing portion 14 and the second opposing portion 15 are separated, and the movable cam portion 24b has an oblique edge that slopes from below the claw portion 23 upward in the direction of travel of the first opposing portion 14.

[0050] Therefore, when changing the posture of the workbench from the folded position P2 to the unfolded position P1, the operator does not need to manually rotate the opening / closing member 20. Instead, the operator simply needs to move the brace 11 from the extended state to the retracted state while keeping the opening / closing member 20 in the closed position Q. When the first opposing part 14 and the second opposing part 15 come into close proximity, the opening / closing member 20 can automatically rotate and lock.

[0051] As shown in Figure 9(A), when the first brace member 12 and the second brace member 13 are slid from the extended state to the contracted state, the opening / closing member 20 is held in the closed position Q by the tensioning means 28, as described above.

[0052] Therefore, when the first opposing portion 14 and the second opposing portion 15 are brought closer together, the movable cam portion 24b comes into contact with the fixed cam portion 26b, as shown in Figure 9(B), and generates an upward force as the first opposing portion 14 moves forward (indicated by the arrow F in the figure). As a result, the opening / closing member 20 rotates around the pivot 19 in the direction toward the open position R, against the tensioning means 28.

[0053] As a result, as shown in Figure 9(C), the claw portion 23 rides up onto the upper edge of the tongue piece 25 and moves forward in that state. At this time, the tensioning means 28 elastically biases the opening / closing member 20 toward the closed position Q, so the claw portion 23 slides while remaining elastically in contact with the upper edge of the tongue piece 25.

[0054] Then, when the first opposing portion 14 and the second opposing portion 15 approach each other at a predetermined position, as shown in Figure 9(D), the claw portion 23 moves over the tongue piece 25, causing the opening / closing member 20 to rotate toward the closed position Q by the tensioning means 28. As a result, the locking portion 24a of the claw portion 23 engages with the locked portion 26a of the tongue piece 25, and the locking device 16 is automatically locked.

[0055] (Another embodiment relating to the biasing means) Figures 10 to 12 show another embodiment of the locking device 16. In this other embodiment, the configuration of the biasing means 27 differs from the embodiment shown in Figures 1 to 9. The other configurations are the same as in the above embodiment, and therefore the same components are indicated by the same reference numerals.

[0056] Regarding the biasing direction of the biasing means 27 in the present invention, specifically the "direction in which the locking portion 24a is locked to the locked portion 26a," in the above embodiment, this direction is the rotational direction around the pivot 19. For this reason, the biasing means 27 is composed of a tensioning means 28 such as a coil spring.

[0057] In contrast, in the embodiments shown in Figures 10 to 12, the biasing direction of the biasing means 27 is set to the direction in which the first brace member 12 moves away from the second brace member 13, thereby biasing the opening / closing member 20 in the direction in which the "locking portion 24a is locked to the locked portion 26a". Specifically, the biasing means 27 is configured by interposing an elastically deformable bushing 30 made of resin, rubber, or the like, located between the pivot hole 20c supported by the pivot 19 in the arm portion 20a of the opening / closing member 20 and the pivot shaft portion 21b of the pivot 19 that supports the pivot hole 20c.

[0058] In this case, as shown in Figure 12(A), the relationship between the locking means 17 and the locked means 18 is such that when the opening / closing member 20 is rotated at the center C1 of the pivot 19 toward the closed position Q with the first opposing part 14 and the second opposing part 15 in contact with each other, the locking part 24a does not fit into the locked part 26a and comes into contact with it from above, thereby preventing rotation. That is, the distance D from the center C1 of the pivot 19 to the locking part 24a is configured to be slightly shorter than in the above embodiment.

[0059] Therefore, as shown in Figure 12(C), when the opening / closing member 20 is strongly rotated downward while the locking portion 24a is in contact with the locked portion 26a from above and its rotation is prevented, the bush 30 elastically deforms, causing the opening / closing member 20 to move slightly forward from the center C1 of the pivot 19. As a result, as shown in the figure, the distance DA from the center C1 of the pivot 19 to the locking portion 24a becomes larger than the distance D described above, so that the locking portion 24a moves to a position aligned with the locked portion 26a, and the opening / closing member 20 is rotated to the closed position Q.

[0060] Figures 12(B) and 12(D) show the relationship between the pivot portion 21b of the pivot 19 fixed to the first brace member 12, the bush 30, and the pivot hole 20c of the opening / closing member 20.

[0061] Figure 12(B) shows the state when the locking portion 24a is in contact with the locked portion 26a and rotation is prevented (the state shown in Figure 12(A)). At this time, the center C1 of the support shaft portion 21b and the center C2 of the support hole 20c coincide and are concentric.

[0062] In contrast, Figure 12(D) shows the locked state where the opening / closing member 20 is pushed down to the closed position Q, and the locking portion 24a is locked to the locked portion 26a. At this time, the center C2 of the pivot hole 20c is moved by a distance m toward the locked portion 26a with respect to the center C1 of the support shaft portion 21b. This movement is caused by the elastic deformation of the bush 30, and since a compression deformation portion 30p is formed in the bush 30 by the pivot hole 20c of the opening / closing member 20, an elastic biasing force MF acts on the opening / closing member 20 in the direction that locks the locking portion 24a to the locked portion 26a due to its elastic restoring force.

[0063] As a result, even when vibration or other external forces act on the brace 11 while it is locked by the locking device 16, the opening / closing member 20 is prevented from rotating from the closed position Q to the open position R. Moreover, a lock without any rattle is possible between the locking means 17 and the locked means 18.

[0064] Incidentally, regarding the embodiments of the biasing means 27, in the embodiments shown in Figures 1 to 9, the biasing means 27 is composed of a tensioning means 28 such as a spring, and in the embodiments shown in Figures 10 to 12, the biasing means 27 is composed of an elastically deformable bushing 30, and these have been described separately. However, an embodiment in which both configurations (tensioning means 28 and bushing 30) are simultaneously provided in the opening / closing member 20 may also be provided. [Explanation of Symbols]

[0065] P1 Deployment posture P2 Folding position PM intermediate posture 1A, 1B Legs 2 Top panel 2A, 2B Top 3 Connection means 4 Pillars 5 horizontal bars 6. Push-up Rod 7 Extension rod 8. Oshiage Link 9. Click the link 10 casters 11 Brace 12. First brace material 12a Outer material 12b Inner material 13. Second brace material 14. First opposing section 15. Second opposing section 16 Locking device 17 Locking mechanism Q closed position R open position 18 Locking means 19 Axis 20 Opening and closing member 20a Arm section 20b Operation section 20c shaft support hole 20d pinch part 20e Stopper 21 volts 21a Screw shaft portion 21b Support shaft 21c flange section 22 nuts 23 Nail area 24a Locking part 24b Moving cam section 25 Tongue piece 26a Locked part 26b Fixed cam section 27. Biasing means 28. Tensile means 29a, 29b stop part L biasing direction line 30 Bush 30p Compression deformation section C1 Axis Center Center of the C2 support hole

Claims

1. In a brace configured such that a first brace member and a second brace member slide against each other in the axial direction, allowing the brace to expand and contract between a contracted state and an extended state, The first brace member (12) and the second brace member (13) are provided with a first opposing portion (14) and a second opposing portion (15) that are close together when in the contracted state and separate when in the extended state, and a locking device (16) is configured between the two opposing portions. The locking device (16) is configured with a locking means (17) that is rotatably mounted on the first opposing portion (14) via a pivot (19) intersecting it and has a locking portion (24a) at its tip, and a locked means (18) that is mounted on the second opposing portion (15) and has a locked portion (26a), The locking means (17) rotates between a closed position (Q) in which the rotation angle is closed so as to be aligned with the first opposing portion (14) and an open position (R) in which the rotation angle is opened so as to be separated from the first opposing portion (14). A brace locking device characterized in that, when the first opposing portion (14) and the second opposing portion (15) are in close proximity to each other, the locking means (17) is rotated to the closed position (Q) toward the locked means (18), the locking portion (24a) is locked to the locked portion (26a), thereby locking the first brace material (12) and the second brace material (13) so that they cannot slide, and when the locking means (17) is rotated toward the open position (R) away from the locked means (18), the locking portion is released from the locked portion, thereby unlocking the first brace material and the second brace material so that they can slide.

2. The locking device for a brace according to claim 1, wherein the locking device (16) is provided with a biasing means (27) that biases the locking means (17) in the direction that locks the locking portion (24a) to the locked portion (26a) when the locking means (17) is rotated to the closed position (Q).

3. The locking device (16) is configured with a cam mechanism consisting of a fixed cam portion (26b) and a movable cam portion (24b) provided on each of the locking means (18) and locking means (17) that are opposite to each other when the first opposing portion (14) and the second opposing portion (15) are separated. The brace locking device according to claim 2, characterized in that when the locking means (17) is rotated to the closed position (Q), the first opposing portion (14) and the second opposing portion (15) are moved to move closer to each other, the moving cam portion (24b) moves along the fixed cam portion (26b) and rotates the locking means (17) toward the open position (R) against the biasing means (27), and when the locking means (17) overcomes the locked means (18), the biasing means (27) rotates the locking means (17) toward the closed position (Q).

4. In a workbench that can change its posture from an unfolded position (P1) in which the left and right top plates (2A) (2B), each supported by left and right legs (1A) (1B), are positioned on the same plane, to a folded position (P2) in which the left and right legs (1A) (1B) are moved in a direction toward each other and the left and right top plates (2A) (2B) are folded in a mountain-fold position, The retractable brace (11) is positioned between the leg body and the tabletop, and both ends of the brace are pivotally connected to the leg body and the tabletop, respectively, and when the workbench changes position from the unfolded position (P1) to the folded position (P2), the brace (11) extends and overlaps with the tabletop as it approaches it. The locking means (17) of the locking device (16) is configured to move closer to the top plate when rotated from the closed position (Q) to the open position (R). A brace locking device for a workbench according to claim 1, 2, or 3, characterized in that when the workbench is changed from an unfolded position (P1) to a folded position (P2) with the locking means (17) rotated to the open position (R), the locking means (17) is pushed by the top plate and rotated to the closed position (Q).

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