Hatch device for scaffolding boards

Abstract

To provide a hatch device allowing the opening of a scaffolding board freely opening / closing.SOLUTION: In a constitution in which an attitude keeping mechanism (16) keeping a lid body set in an open attitude (P2) by setting a pair of lateral link arms (20) in a fixed locked state (K) in a standing attitude (Q2), and a releasing mechanism (24) for releasing the lock and setting in a lock-released state (K) to thereby set the link arms (20) in a folded attitude (Q1) are provided, an arm linkage mechanism (27) is provided composed to keep the lock-released state (K) of the other link arm (20), even when one link arm (20) is set in the lock-released state directly with the fingertips, not by a regular usage of operating the releasing mechanism (24) by a worker.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a hatch device in which an opening connecting the upper and lower spaces of a scaffolding board is closed by a lid that can be opened and closed freely, and which is provided with a posture maintaining mechanism for maintaining the lid in an upright, open position. [Background technology]

[0002] In a conventional temporary scaffold constructed with work floors in upper and lower levels using scaffolding boards, some of the scaffolding boards are provided with a hatch device having an opening that connects the upper and lower spaces and a lid that can be freely opened and closed to close the opening, and a ladder, staircase, or other lifting means is installed facing the opening. This allows workers to move between the upper and lower floors by raising and lowering the lifting means with the lid in the open position to open the opening.

[0003] In addition, similar hatch devices are also installed on suspended scaffolding, which is constructed by hanging scaffolding boards with chains or the like, and are used for emergency evacuation and other purposes.

[0004] Such hatch devices normally close the opening with a lid to prevent workers from falling, but for the above-mentioned purpose, the opening is opened by raising the lid, and after the purpose is achieved, the opening is closed again by returning the lid to the closed position. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3820360 [Patent Document 2] Patent No. 5978148 Summary of the Invention [Problem to be solved by the invention]

[0006] It is desirable that the lid of the hatch device be configured to rotate around a pivot at the base end pivotally connected to the frame of the opening between a closed position in which the opening is closed and an open position in which the opening is opened by standing up.

[0007] At this time, the lid body easily rotates from the upright open position to the closed position due to its own weight, etc., so it is desirable to provide a position holding mechanism for holding the lid body in the open position.

[0008] The position holding mechanism can be constructed using various means, but in order to enable the lid body to rotate smoothly between the closed position and the open position and to hold the lid body in the open position securely and stably, it is preferable to construct it using an operating shaft that is rotatably supported on the lid body, a pair of left and right guide support means provided along the frame portions on both sides of the opening, and a pair of left and right link arms that are straddled between the shaft ends at both ends of the operating shaft and the guide support means.

[0009] According to this, when the lid body is rotated from the closed position to the open position, the tip of the link arm, which is pulled by the operating shaft, moves backward along the guide path of the guide support means, and the engagement portion provided at the tip of the link arm in the upright position is dropped and fitted into a locking groove provided at the end of the guide path, so that the fixed and locked link arm can reliably maintain the open position of the lid body.

[0010] Conventionally, the release means for releasing the hold of the posture holding mechanism configured as described above has been configured by providing an operating piece on the link arm, and the operator (user) lifts the link arm via the operating piece to release the fixed lock. However, when the lid body is rotated toward the closed position, the lock on the link arm moves in the folding direction, making it dangerous and undesirable for the operator's fingers to approach the link arm.

[0011] Therefore, in order to release the open position of the lid body, it is preferable to provide a release mechanism that is configured to rotate the operating shaft in the release direction by providing an operating lever on the operating shaft, thereby rotating the link arm in the release direction and lifting the engaging portion out of the locking groove to release the lock.

[0012] However, when unlocking the cover, the worker (user) may visually recognize the link arms in an upright position on both sides of the open cover body, and may recognize that they can release the lock and return the cover body to the closed position by rotating the link arms directly with their fingertips, as in the case of conventional technology, and causing the engaging portion to escape from the lock groove.In this case, there is a risk that the worker will try to release the lock by directly pushing the link arms with their fingertips, rather than operating the operating lever in the normal way.

[0013] However, in such a case, as soon as one of the pair of left and right link arms is unlocked, both link arms are unlocked, causing the lid body to rotate in the closing direction all at once due to its own weight, and at the same time the link arms move in the folding direction, which poses a risk of the operator's fingers getting caught.

[0014] The present invention aims to provide a hatch device that has a position-maintaining mechanism that reliably and stably maintains the open position of the lid body using the link arm described above, and that ensures safety when changing the position of the lid body from the open position to the closed position. [Means for solving the problem]

[0015] Therefore, the first means of the present invention is a hatch device that closes an opening that communicates the upper and lower spaces of a scaffolding board with a lid that can be opened and closed freely, and the lid is configured to rotate around a pivot at its base end that is pivotally connected to the frame of the opening between a closed position in which the opening is closed and an open position in which the opening is opened by standing up, and is provided with a posture holding mechanism that holds the lid in the open position and a release mechanism that releases the holding, and the posture holding mechanism is composed of an operating shaft that is rotatably supported on the lid, and a pair of left and right link arms that are provided between the shaft ends at both ends of the operating shaft and the left and right frame parts of the opening, and when the lid is rotated from the open position to the closed position, The lid is pushed by the operating shaft and moves forward to assume a folded position along the side frame of the opening, and when the lid is rotated from the closed position to the open position, it is pulled by the operating shaft and moves backward to assume an upright position, and in the upright position, the engaging portions of the link arms are dropped and fitted into locking grooves provided on both the left and right frame portions to assume a fixed and locked state, and the open position of the lid is maintained in this fixed and locked state, and the release mechanism is configured to transmit the rotation of the operating shaft rotated by the operating piece in the release direction to the link arm, thereby rotating the link arm in the release direction, and to lift the link arm, which is in the fixed and locked state, out of the locking groove to assume an unlocked state.

[0016] The second means of the present invention is a hatch device that closes an opening that connects the upper and lower spaces of a scaffolding board with a lid that can be opened and closed freely, and the lid is configured to rotate around a pivot at the base end that is pivotally connected to the frame of the opening between a closed position in which the opening is closed and an open position in which the opening is opened by standing up, and the hatch device is provided with a position holding mechanism that holds the lid in the open position and a release mechanism that releases the holding, and the position holding mechanism is provided with an operating shaft that is pivotally supported on the lid and a release mechanism that releases the holding, and the position holding mechanism is provided with an operating shaft that is pivotally supported on the lid and a release mechanism that releases the holding, and the position holding mechanism is provided with an operating shaft that is pivotally supported on the lid and a release mechanism that releases the holding mechanism ... The cover is constructed by a pair of left and right guide support means provided along the side frame portions, and a pair of left and right link arms provided between the shaft end portions at both ends of the operating shaft and the guide support means, the link arms have the shaft end portions inserted into the shaft support holes at the base ends, and the engagement portions at the tip ends are slidably engaged with the guide paths of the guide support means, and when the cover is rotated from the open position to the closed position, the link arms are pushed by the operating shaft to move the engagement portions forward along the guide paths, thereby taking a folded position along the side frame portions of the opening, and the cover is rotated from the closed position to the closed position. When rotated toward the open position, the operating shaft pulls the engaging portion backward along the guide path, thereby taking an upright position, and the engaging portion drops and fits into a locking groove connected to the end of the guide path, thereby taking a fixed, locked state, and the open position of the lid body is maintained in this fixed, locked state. The release mechanism is composed of an operating piece that rotates the operating shaft, a shaft end of the operating shaft, and a shaft support hole of a link arm into which the shaft end is inserted, and is configured to transmit rotation of the operating shaft in the release direction to the link arm, thereby rotating the link arm in the release direction and lifting the engaging portion, which has been set in the fixed, locked state, out of the locking groove and into an unlocked state, and an arm interlocking mechanism is formed between the shaft end and the shaft support hole, and the arm interlocking mechanism is configured so that, with regard to rotation in the release direction transmitted from the link arm to the shaft end, when the link arm is rotated within a range of angles from the fixed, locked state to the unlocked state, the rotation of the link arm is not transmitted to the shaft end, or the shaft end is rotated by an angle smaller than the angle.

[0017] In a preferred embodiment, the engaging portion is formed by a pin that protrudes laterally from the tip of the link arm, and the guide path of the guide support means is formed by a slot with upper and lower edge portions that hold the engaging portion from above and below while it is slidably inserted, and the locking groove is formed by a recess that is recessed downward from the end of the slot, and the upper edge portion of the slot is extended to a position above the locking groove to form a means for regulating the upward movement of the engaging portion.

[0018] In a further preferred embodiment, the operating piece constituting the release mechanism is constituted by an operating lever with the operating shaft inserted into a support hole at the base end, and is configured so that when the operating piece is rotated in the release direction, the operating shaft is rotated in the release direction via an interlocking delay mechanism provided between the support hole of the operating piece and the operating shaft, and the interlocking delay mechanism is configured so that when the operating piece is rotated in the release direction, the rotation of the operating piece is not transmitted to the operating shaft until the operating piece rotates beyond a predetermined angle. [Effects of the Invention]

[0019] According to the present invention, the lid body 8 is rotated between the folded position Q1 and the standing position Q by the position holding mechanism 16 while the pair of left and right link arms 20L, 20R are guided by the pair of left and right guide support means 19L, 19R, so that the rotation operation is smooth. Moreover, the lid body 8 in the open position P2 is supported from both the left and right sides by the link arms 20L, 20R which are in the fixed lock state L, so the open position P2 is held reliably and stably, allowing for safe work.

[0020] Furthermore, due to the configuration of the arm interlocking mechanism 27, with respect to the link arms 20L, 20R holding the lid body 8 in the open position P2, even if an operator rotates one of the link arms 20L (20R) with his / her fingertip to move the engaging portion 21 upward from the fixed lock state L to the unlocked state K, the other link arm 20R (20L) maintains the fixed lock state L and holds the lid body 8 in the open position P2, thereby preventing the risk of injury to the fingers, etc. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a scaffolding board provided with a hatch device according to one embodiment of the present invention, with the lid body in a closed position to close the opening. FIG. [Figure 2] This is an oblique view showing a scaffolding board equipped with a hatch device according to one embodiment of the present invention, with the lid in an open position to open the opening. [Figure 3] 1A shows a hatch device, in which FIG. 1A is a perspective view showing the opening and the lid body separated, and FIG. 1B is a perspective view showing the tip of the link arm and the guide means. [Figure 4] FIG. 2 is a perspective view showing the cover in an open position. [Figure 5] Regarding the posture holding mechanism and the release mechanism, (A) is an oblique view showing the entire mechanism, (B) is an oblique view showing an enlarged view of one link arm in a fixed and locked state, and (C) is an oblique view showing an enlarged view of the other link arm in a fixed and locked state. [Figure 6] Regarding the operation of the posture holding mechanism and the release mechanism, (A) is a side view showing the state in which the lid body is in the closed posture, (B) is a side view showing the state in which the lid body is rotating from the closed posture to the open posture, and (C) is a side view showing the state in which the lid body in the open posture is held by a link arm that is in a fixed lock state. [Figure 7] Regarding the operation of the position holding mechanism and the release mechanism, (A) is a side view showing the operation method for changing the lid body from the open position to the closed position, and (B) is a side view showing the state in which the lid body is rotating from the open position to the closed position. [Figure 8] 1 is a perspective view showing the relationship between an operating shaft, an operating piece, and a shaft support hole of a link arm in one embodiment of a release mechanism. FIG. [Figure 9] Regarding the release mechanism, (A) and (B) are cross-sectional views showing the relationship between the pivot hole of the operating piece and the operating shaft, (C) and (D) are cross-sectional views showing the relationship between the shaft end of the operating shaft and the pivot hole of the link arm, and (E) is a side view explaining the relationship between the rotation angle of the operating piece in the release direction and the rotation angle of the link arm. [Figure 10]1A is a side view showing the operation of the operation piece, operation shaft, and link arm when the operation piece is rotated in the release direction by the first stage, and FIG. 1B is an enlarged view. [Figure 11] 10A is a side view showing the state when the operating piece is rotated to the second stage in the release direction, and FIG. 10B is an enlarged view showing the operation of the operating piece, the operating shaft, and the link arm. [Figure 12] 10A is a side view showing the state when the operating piece is rotated to the third stage in the release direction, and FIG. 10B is an enlarged view showing the action of the operating piece, the operating shaft, and the link arm. [Figure 13] 10 is a side view showing the operation of the arm interlocking mechanism between the link arm and the operating shaft when the link arm is rotated in the release direction. FIG. [Figure 14] (A) is an oblique view showing the state in which the left and right link arms are in an upright position in a fixed lock state, (B) is an oblique view showing the state in which one of the link arms has been rotated in the release direction, and (C) is an enlarged view showing the unlocked state in which the engagement portion of one of the link arms has escaped from the lock groove. DETAILED DESCRIPTION OF THE INVENTION

[0022] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] 1 and 2 illustrate a scaffolding board 1 equipped with a hatch device. In the illustrated example, a scaffolding board for constructing a temporary scaffolding is shown, but the present invention is not limited to this and may also be a scaffolding board for constructing a suspended scaffolding.

[0024] The scaffolding board 1 forms a rectangular framework with both ends of a pair of parallel girder side frames 2, 2 connected by a gable side frame 3, and in the example shown in the figure, it is used by being erected on the cross members of the temporary scaffolding via hook fittings fixed to each end of the girder side frames 2, 2.

[0025] The rectangular framework is located in the middle in the longitudinal direction and has girder side frames 2, 2 connected by an intermediate frame 4, thereby forming a first frame portion 1A and a second frame portion 1B.

[0026] The first frame 1A has floor plates 5 laid thereon, providing a work floor. In contrast, the second frame 1B has an opening 7 that connects the upper and lower spaces of the scaffolding board 1, and is provided with a lid 8 that can be freely opened and closed to close the opening 7, thereby constituting a hatch device 6. In this case, the lid 8 is provided with a lid plate 9 made of the same material as the floor plates 5, and is configured so that when closed, the lid plate 9 is supported flush with the floor plates 5, thereby providing a work floor.

[0027] (Hatch device) As shown in Figure 3(A), the opening 7 is formed by a framework of girder side frames 2, 2, end side frame 3, and intermediate frame 4, which respectively constitute the opening base frame 7a, opening tip frame portion 7b, and opening both side frame portions 7c, 7d.

[0028] 3(A) and 4, the lid body 8 is formed into a rectangular frame by a lid base frame portion 8a, a lid tip frame portion 8b, and lid side frame portions 8c and 8d, and the frame is covered from above with the lid plate 9, which is fitted into the opening 7 to close the opening 7. In addition, in the closed state, the lid body 8 is placed on a placing portion formed on the frame portion of the opening 7 and is supported from below.

[0029] Pivots 10 protruding from both ends of the lid base frame 8a that constitutes the framework of the lid 8 are supported in pivot holes formed in the opening side frame portions 7c and 7d, so that the lid 6 is configured to rotate about the pivot 10 on the base end side between a closed position P1 in which the opening 7 is closed and an open position P2 in which the lid 6 tilts and stands up to open the opening 7. The relationship between the pivots 10 and the pivot holes may be reversed; that is, the pivots 10 may be provided on the opening side frame portions 7c and 7d, and the pivot holes may be provided on both ends of the lid base frame 8a.

[0030] (Closing locking mechanism) A closure locking mechanism 11 is provided for releasably locking both ends of the lid tip frame portion 8b to the opening side frame portions 7c, 7d when the lid is in the closed position P1. The closure locking mechanism 11 is composed of a pair of rod members 12 having tip locking portions 12a that protrude freely forward and backward from both ends of the lid tip frame portion 8b, and locking holes (not shown) provided in the opening side frame portions 7c, 7d so that the tip locking portions 12a can be inserted and locked.

[0031] The rod member 12 is supported so as to be freely slidable along the lid tip frame portion 8b via a support bracket 13 provided on the underside of the lid plate 9, and is resiliently biased by a spring 14 to protrude the tip engagement portion 12a.

[0032] The tail end of the rod member 12 is bent back into an approximately U shape to form a grip portion 12b, and the cover plate 9 has a window hole 15 that faces the grip portions 12b of the pair of left and right rod members 12, 12 (see Figure 1).

[0033] Although not shown in the figure, a guide tapered surface is formed on the tip engaging portion 12a, and when the lid body 8 is rotated from the open position P2 to the closed position P1, the guide tapered surface rubs against the boss portion of the engaging hole, causing the rod member 12 to slide against the spring 14, thereby retracting the tip engaging portion 12a, and at the same time, when the tip engaging portion 12a faces the engaging hole, it is protruded by the spring 14 and inserted and engaged, thereby forming an automatic engaging and locking structure.

[0034] To open the opening 7, when the lid 9, which has been locked by the closure locking mechanism 11, is changed from the closed position P1 to the open position P2, the operator inserts his fingers into the window hole 15 and grasps the grip portions 12b, 12b of the pair of left and right rod members 12, 12, and moves the rod members 12, 12 against the spring 14 in a direction that brings the grip portions 12b, 12b closer to each other. This causes the tip locking portion 12a to be extracted from the locking hole, and the lock is released. As a result, the lid 8 can be rotated about the pivot 10 in the upright direction to take the open position P2.

[0035] (Posture holding mechanism) 3 to 5, the position maintaining mechanism 16 is configured with an operating shaft 18 rotatably supported via a bracket 17 on the underside of the cover plate 9 of the cover 8, a pair of left and right guide support means 19L, 19R (sometimes simply referred to as guide support means 19 when no distinction is made between left and right) provided along the frame portions 7b, 7c on both sides of the opening 7, and a pair of left and right link arms 20L, 20R (sometimes simply referred to as link arms 20 when no distinction is made between left and right) provided between shaft end portions 18a at both ends of the operating shaft 18 and the guide support means 19.

[0036] The link arm 20 has a base end into which the shaft end 18a of the operating shaft 18 is inserted, and an engaging portion 21 consisting of a pin protruding from the side of the tip end is slidably engaged with a guide path 22 provided in the guide support means 19. In this case, the guide path 22 is formed by a slot having upper and lower edge portions 22a, 22b that hold the engaging portion 21 from above and below in a state in which it is slidably inserted, and a lock groove 23 is formed by a recess recessed downward from the end of the slot, and the upper edge portion 22a of the slot is extended to a position above the lock groove 23, and this extension constitutes an upward movement restricting means 22c that restricts the upward movement of the engaging portion 21.

[0037] In addition, the guide support means 19L, 19R shown in the drawings have a pair of recesses at both ends of the guide path 21, but this is so that the same configuration of guide support means 19 can be used for both the left-handed 19L and the right-handed 19R, and it should be understood that the recess at the tip side of the guide path 22 (the side facing the opening base frame portion 7a) is functionally unnecessary.

[0038] As a result, engaging portion 21 is engaged so as to be slidable in the direction of forward and backward movement along guide path 22. Hereinafter, movement toward the tip side of guide path 22 (the side facing open tip frame portion 7b) will be referred to as "forward movement," and conversely, movement toward the base side of guide path 22 (the side facing open base frame portion 7a) will be referred to as "rearward movement."

[0039] As shown in Figure 6 (A), when the cover body 8 is in the closed position P1, the link arm 20 is in the folded position Q1 along the opening side frame portion 7c (7d) between the shaft end portion 18a of the operating shaft 18 and the guide path 22, and the engagement portion 21 is moved forward and positioned at the tip side of the guide path 22.

[0040] When the cover body 8 is rotated from this state toward the open position P2, as shown in Figure 6 (B), the base end of the link arm 20 is pulled by the shaft end 18a of the operating shaft 18, causing the engaging portion 21 to move backward along the guide path 22, while tilting in the upright direction from the engaging portion 21 toward the shaft end 18a.

[0041] 6(C), when the lid body 8 reaches the open position P2, the link arm 20 is fixed and locked by the engaging portion 21, which has moved backward along the guide path 22, dropping into and fitting into the lock groove 23 (hereinafter, this state will be referred to as the "fixed lock state L"). As a result, the link arm 20 is prevented from moving forward or backward in the upright position Q2 in which it is inclined and upright from the engaging portion 21 toward the shaft end 18a, and the lid body 8 is held in the open position P2.

[0042] The position holding mechanism 16 is configured to change the position between the folded position Q1 and the standing position Q2 while guiding a pair of left and right link arms 20L, 20R by a pair of left and right guide support means 19L, 19R between shaft end portions 18a, 18a at both ends of an operating shaft 18 pivotally supported on the lid body 8 and frame portions 7c, 7d on both sides of the opening 7. Therefore, by holding the position of the lid body 8 from both the left and right sides, the lid body 8 can be rotated smoothly, and there is no risk of distortion or deformation of the pivot 10.

[0043] The lid body 8 in the open position P2 is supported on both the left and right sides by the link arms 20L, 20R which are fixed in the locked state L, so that it is held securely and stably in the open position P2, and even when subjected to an external force, there is no danger that the lid body 8 will accidentally rotate toward the closed position P1, allowing work to be carried out safely.

[0044] (Release mechanism) In order to change the cover 8 from the open position P2 to the closed position P1, a release mechanism 24 is provided that releases the fixed lock state L of the link arm 20. As shown in Figures 5 and 8, the release mechanism 24 is made up of an operating piece 25 made up of an operating lever that rotates the operating shaft 18, and an interlock delay mechanism 26 provided between the operating piece 25 and the operating shaft 18. Furthermore, an arm interlock mechanism 27 is provided between the shaft end 18a of the operating shaft 18 and the base end of the link arm.

[0045] As shown in Fig. 7(A), when the operator rotates the operating piece 25 with his / her fingertip in the release direction U (the direction in which the operating lever is raised) with the link arm 20 in the upright position Q2, the link arm 20 is rotated in the release direction W via the rotation of the operating shaft 18, and the engaging portion 21 is pulled up and released from the lock groove 23, thereby releasing the fixed locked state (hereinafter, this state is referred to as the "unlocked state K"). As a result, as shown in Fig. 7(B), the engaging portion 21 of the link arm 20 is moved forward along the guide path 21, and the lid body 8 can be rotated from the open position P2 to the closed position P1.

[0046] At this time, the pulled-up locking portion 21 comes into contact with the upward movement restricting means 22c in the unlocked state K in which it has escaped from the locking groove 23, thereby restricting its upward movement, and thereby allowing it to move forward suitably toward the guide path 21 while positioned.

[0047] Now, regarding a mechanism for releasing the fixed lock of link arm 20, to explain a comparative example to the present invention, if a configuration is adopted in which shaft end 18a of operating shaft 18 is directly connected (integrally fixed) to the base end of link arm 20, and operating shaft 18 is directly connected (integrally fixed) to the base end of operating piece 25, the following dangers arise. That is, as a first danger, when an operator touches operating piece 25, operating shaft 18 is immediately rotated, and at the same time the fixed lock of the pair of left and right link arms 20L, 20R is released, and there is a risk that lid body 8 will accidentally rotate toward closed position P1, resulting in the risk of injury to the operator. Furthermore, as a second risk, as described above with regard to the problem to be solved by the invention, if an operator releases the fixed lock state by rotating one of the link arms 20L(R) with his / her fingertip, the operating shaft 18 will be rotated, and the other link arm 20R(L) will also be released from the fixed lock state at the same time, causing the cover body 8 to rotate all at once toward the closed position P1, and there is a risk that the operator's fingers or other parts of the body will be injured by the link arm 20 moving toward the folded position Q1.

[0048] (Interlocking delay mechanism and arm interlocking mechanism) To prevent such danger, the interlock delay mechanism 26 is configured so that when the operating piece 25 is rotated in the release direction, the operation of the operating piece 25 is not transmitted to the operating shaft 18 until the operating piece 25 has rotated beyond a predetermined angle. In other words, the operating piece 25 has play in its rotation in the release direction, which delays the start of rotation of the operating shaft 18. Therefore, when the worker rotates the operating piece 25 with his or her fingertip, the worker can feel the load at his or her fingertip when the rotation is transmitted to the operating shaft 18 (and further to the link arm 20) beyond the play, and can therefore work safely knowing that the fixed lock state L of the link arm 20 will be released.

[0049] Also, with respect to the arm interlocking mechanism 27, in a path opposite to the path that transmits the rotation of the operating shaft 18 in the release direction to the link arm 20, that is, in a path that transmits the rotation of the link arm 20 in the release direction to the shaft end portion 18a of the operating shaft 18, when the link arm 20 is rotated in the release direction W within the range of the angle θx from the fixed lock state L to the unlocked state K, the rotation of the link arm 20 is not transmitted to the shaft end portion 18a, or even if transmission is allowed, the shaft end portion 18a is configured to be rotated only by an angle smaller than the angle θx.

[0050] Therefore, if the operator rotates one of the left and right link arms 20L, 20R with a fingertip and moves the locking portion 21 upward from the fixed lock state L to the unlocked state K, the other link arm 20R (L) maintains the fixed lock state L. Thereby, the open posture P2 of the lid body 8 is maintained, and the lid body 8 does not rotate toward the closed posture P1.

[0051] In the case of the illustrated embodiment, as shown in FIG. 8, the operating shaft 18 is formed by a rod having a square cross section over its entire length, and angular shaft support holes 25a and shaft support holes 20a that are similar in shape to the cross section of the rod are formed at the base end portions of the operating piece 25 and the link arm 20, respectively. The interlocking delay mechanism 26 is configured by inserting the operating shaft 18 into the shaft support hole 25a of the operating piece 25 in a loosely fitting state, and the arm interlocking mechanism 27 is configured by inserting the shaft end portion 18a of the operating shaft 18 into the shaft support hole 20a of the link arm 20 in a loosely fitting state.

[0052] In the embodiment shown in FIG. 8, the cross-sectional shape of the operating shaft 18 is formed as a rectangle having one side X1 and the other side X2 (preferably a square with X1 = X2), the shape of the shaft support hole 25a of the operating piece 25 is formed as a rectangle having one side Y1 and the other side Y2 (preferably a square with Y1 = Y2), and the shape of the shaft support hole 20a of the link arm 20 is formed as a rectangle having one side Z1 and the other side Z2 (preferably a square with Z1 = Z2), and the lengths of the respective sides are configured such that X1 < Y1 < Z1 and X2 < Y2 < Z2.

[0053] In this regard, the relationship between the operating piece 25 and the operating shaft 18 is shown in Figures 9(A) and 9(B). Even if the operating piece 25 is rotated in the release direction U as shown in Figure 9(B) from a state in which the operating shaft 18 is loosely fitted in the center of the shaft support hole 25a of the operating piece 25 as shown in Figure 9(A), the rotation of the shaft support hole 25a of the operating piece 25 is not immediately transmitted to the operating shaft 18. When the operating piece 25 rotates beyond a predetermined angle as shown in Figure 9(B), the shaft support hole 25a and the sides Y and X or corners of the operating shaft 18 abut and engage, and when the operating piece 25 is rotated further, the operating shaft 18 is rotated along with it.

[0054] 9(C) and 9(D) show the relationship between the shaft end 18a of the operating shaft 18 and the shaft support hole 20a of the link arm 20. Even if the shaft end 18a of the operating shaft 18 rotates in the release direction V as shown in FIG. 9(D) in response to the rotation of the operating piece 25 from a state in which the shaft end 18a is loosely fitted in the center of the shaft support hole 29a as shown in FIG. 9(C), the rotation of the shaft end 18a in the shaft support hole 20a is not immediately transmitted to the shaft support hole 20a. When the shaft end 18a rotates beyond a predetermined angle as shown in FIG. 9(D), the sides X and Z or corners of the shaft end 18a and the shaft support hole 20a abut and engage, and when the shaft end 18a rotates further, the link arm 20 rotates together with the shaft support hole 20a.

[0055] 9(E) shows the action of the above configuration when the operating piece 25 is rotated in the release direction U with the link arm 20 in the fixed lock state L and in the upright position Q2. The operating piece 25 is rotated sequentially from the standby position 0 to positions a, b, and c. When the operating piece 25 is rotated from position b to position c, the link arm 20 is lifted by an angle θc, causing the engaging portion 20 to escape from the lock groove 22.

[0056] When the operating piece 25 is rotated from the standby position 0 to the position a in the first stage, it is rotated by an angle θa as shown in FIG. 10, but this rotation range is set as the play of the operating piece 25. In other words, the rotation of the operating piece 25 is not transmitted to the operating shaft 18, so the operating shaft 18 does not rotate. Only when the operating piece 25 is rotated to the position a does the shaft support hole 25a and the side of the operating shaft 18 come into contact with each other. Y and side X or corners abut and interlock.

[0057] Subsequently, in the second stage, when the operating piece 25 is rotated from position a to position b, it is rotated by angle θb, as shown in Figure 11. At this time, the operating shaft 18 is rotated in the release direction V by the same angle θb via sides Y and X where the pivot hole 25a and the operating shaft 18 abut. However, in this second stage, the rotation of the operating shaft 18 is not transmitted to the pivot hole 20a of the link arm 20, and the link arm 20 does not rotate. In the second stage, only when the operating shaft 18 is rotated by angle θb do the operating shaft 18 and sides X and Z or corners of the pivot hole 20a abut and engage with each other.

[0058] Then, as a third step, when the operating piece 25 is rotated from the position b to the position c, it is rotated by an angle θc as shown in Fig. 12. At this time, the operating shaft 18 is rotated by the same angle θc along with the operating piece 25 via the mutually interlocking sides Y and X or the corners, and the link arm 20 is rotated by the same angle θc in the release direction W via the mutually interlocking sides X and Z or the corners. At this time, the engaging portion 20 of the link arm 20 is released from the lock groove 22, and the fixed locked state L moves to the unlocked state K.

[0059] 13 and 14 show the action of the arm interlocking mechanism 27 when the operator rotates only the link arm 20 in the release direction W directly with the fingers or the like, rather than rotating the operating shaft 18 in the normal manner.

[0060] The arm linkage mechanism 27 inserts one shaft end 18a into the shaft support hole 20a of one of the left and right link arms 20L and 20R, fixes it in a predetermined posture, and inserts the other shaft end 18a into the center of the shaft support hole 20a of the other link arm 20L. In the case of the illustrated example, one shaft end 18a is fixed to one link arm 20R by screwing a screw 28 to the shaft end face. Hereinafter, one link arm 20R will be described as the fixed-side link arm 20R, and the other link arm 20L will be described as the floating-side link arm 20L.

[0061] As described above, the floating-side link arm 20L is configured such that sides X and Z are X < Z between the shaft end 18a of the operating shaft 18 and the shaft support hole 20a of the link arm 20L. When the operating shaft 18 is rotated in the release direction V by the operating piece 25 in the normal usage method, when the shaft end 18a is rotated to an angle θb, the side X or the corner contacts the side Z or the corner of the shaft support hole 20a, and when the shaft end 18a is further rotated to an angle θc, the shaft support hole 20a of the link arm 20L rotates together, and the link arm 20L is configured to be rotated in the release direction W by the same angle θc.

[0062] (Function when the fixed-side link arm is rotated) Therefore, the function when the fixed-side link arm 20R of the pair of left and right link arms is rotated to an angle θc in the release direction W, rather than in the normal usage method, will be described. When the link arm 20R is rotated to an angle θc, the engaging portion 20 moves upward from the fixed lock state L locked in the lock groove 22 to the unlocked state L where the locking is released. However, since the upward movement of the engaging portion 20 is restricted by the upward movement restricting means 22c, it does not rotate beyond the angle θc.

[0063] When the fixed-side link arm 20R is rotated to an angle θc, the operating shaft 18 fixed thereto also rotates to an angle θc. However, the floating-side link arm 20L rotates only by an angle θx (θx = θc - θb) smaller than the angle θc. Therefore, the floating-side link arm 20L maintains the locking portion 21 in the fixed lock state L.

[0064] (Operation when the movable side link arm is rotated) Conversely, the operation when the movable side link arm 20L of the pair of left and right link arms is rotated by an angle θc in the release direction W will be described.

[0065] When the movable side link arm 20L is rotated by the angle θc, the engaging portion 20 of the arm 20L moves upward from the fixed locked state L where it is locked in the locking groove 22 to the unlocked state L where the locking is released. However, the operation shaft 10 rotates only by an angle θx (θx = θc - θb) smaller than the angle θc. For this reason, the fixed side link arm 20R does not rotate up to the angle θc and maintains the fixed locked state L. Incidentally, also in this case, since the upward movement of the locking portion 20 is restricted by the upward movement restricting means 22c, the movable side link arm 20L does not rotate beyond the angle θc.

[0066] (Another embodiment) The arm interlocking mechanism 27 configured by forming the side X of the shaft end portion 18a of the operation shaft 18 and the side Z of the shaft support hole 20a such that X < Z can form the relationship between the rotation angle θb until the side X and the side Z or the corner portion abut in the movable side link arm 20L and the rotation angle θc for moving the locking portion 21 of the link arm 20L upward from the fixed locked state L to the unlocked state K as θb > θc.

[0067] In this case, even if the operation shaft 18 is rotated by the same angle θc by rotating the fixed side link arm R by the angle θc in the release direction W, the rotation of the operation shaft 18 is not transmitted to the shaft support hole 20a of the movable side link arm 20L, so the movable side link arm 20L does not rotate.

[0068] Conversely, even if the movable side link arm L is rotated by the angle θc in the release direction W, the rotation of the movable side link arm 20L is not transmitted to the operation shaft 18, so the fixed side link arm R does not rotate.

[0069] According to the configuration of the arm interlocking mechanism 27 as described above, regarding the link arms 20L and 20R that hold the lid body 8 in the open position P2, even if an operator rotates one of the link arms 20L (20R) with a fingertip in a non-normal usage method to move the locking portion 21 upward from the fixed lock state L to the unlocked state K, the other link arm 20R (20L) maintains the fixed lock state L. Therefore, the lid body 8 can be held in the open position P2, and it is possible to prevent risks such as injury to the operator's finger.

[0070] (Yet another embodiment) In the case of the illustrated embodiment, the arm interlocking mechanism 27 is configured by forming the cross-sectional shape of the operation shaft 18 (shaft end portion 18a) and the hole shape of the shaft support hole 20a as rectangular, with sides X and Z formed such that X < Z. However, the present invention is not limited to such a configuration. For example, a rib extending in the axial direction is provided on the surface of the operation shaft 18 composed of a rod having a substantially circular cross-section, and a groove for loosely inserting the rib is provided in the shaft support hole 20a of the link arm 20 into which the operation shaft 18 is inserted. By forming a space that allows play between the rib and the groove side surface with respect to rotation in the release direction, the arm interlocking mechanism 27 may be configured. In this case, between the rib of the operation shaft 18 and the groove of the shaft support hole 20a, when one is rotated to an angle θc as described above, a relationship can be formed such that the other rotates only by an angle θx (θx = θc - θb) smaller than the angle θc. Thereby, the same operational effects as those of the above embodiment can be obtained.

Explanation of Reference Numerals

[0071] 1 scaffold board 1A first frame portion 1B second frame portion 2 side frame on the digit side 3 side frame on the wife side 4 intermediate frame 5 floor board 6 hatch device 7 opening 7a opening base frame portion 7b opening tip frame portion 7c, 7d opening side frame portions 8 lid body 8a Lid base frame 8b Lid tip frame 8c, 8d Lid frame on both sides 9 Lid plate 10 Axis 11 Closure locking mechanism 12 Rod member 12a Tip locking part 12b Grip section 13 Support bracket 14 Spring 15 Window hole 16 Posture holding mechanism 17 Bracket 18 Operation axis 18a Shaft end 19L, 19R Guide and support means 20L, 20R link arms 20a Axle support hole 21 Engagement portion 22 Guideway 22a Upper edge 22b Lower edge 22c Upward movement control means 23 Lock groove 24 Release mechanism 25 Operation piece 25a Pivot hole 26 Interlocking delay mechanism 27 Arm interlocking mechanism 28 bis P1 closed position P2 open position Q1 Folding position Q2 Standing posture U, V, W release direction L Fixed lock state K unlocked

Claims

1. A hatch device in which an opening communicating the upper and lower spaces of a scaffolding board is closed by a lid body so as to be able to be opened and closed freely, and the lid body (8) is configured to rotate around a pivot (10) at the base end pivotally connected to the frame of the opening (7) between a closed position (P1) in which the opening is closed and an open position (P2) in which the opening is opened by standing up, and is provided with a position holding mechanism (16) that holds the lid body in the open position and a release mechanism (24) that releases the holding; The posture holding mechanism (16) is composed of an operating shaft (18) rotatably supported on the cover body (8), and a pair of left and right link arms (20) straddling between shaft end portions (18a) at both ends of the operating shaft and the left and right frame portions of the opening (7), When the lid body is rotated from the open position (P2) to the closed position (P1), the link arm (20) is pushed by the operating shaft and moves forward to assume a folded position (Q1) along the side frame of the opening, and when the lid body is rotated from the closed position (P1) to the open position (P2), the link arm (20) is pulled by the operating shaft and moves backward to assume an upright position (Q2); In the upright position (Q2), the engaging portion (21) of the link arm is dropped into and fitted into the lock grooves (23) provided on the left and right side frame portions to establish a fixed and locked state (L), and the open position (P2) of the lid body is maintained in the fixed and locked state. The release mechanism (24) is configured to transmit the rotation of the operating shaft (18) rotated by the operating piece (25) in the release direction (V) to the link arm (20), thereby rotating the link arm in the release direction (W), and to lift the link arm, which has been set in the fixed lock state (L), out of the lock groove and into an unlocked state (K).

2. A hatch device in which an opening communicating the upper and lower spaces of a scaffolding board is closed by a lid body so as to be able to be opened and closed freely, and the lid body (8) is configured to rotate around a pivot (10) at the base end pivotally connected to the frame of the opening (7) between a closed position (P1) in which the opening is closed and an open position (P2) in which the opening is opened by standing up, and is provided with a position holding mechanism (16) that holds the lid body in the open position and a release mechanism (24) that releases the holding; The position holding mechanism (16) is composed of an operating shaft (18) rotatably supported on the cover body (8), a pair of left and right guide support means (19) provided along the left and right frame portions of the opening (7), and a pair of left and right link arms (20) provided between shaft end portions (18a) at both ends of the operating shaft and the guide support means (19), and the link arms (20) have the shaft end portions (18a) inserted into shaft support holes (20a) at their base ends and have engagement portions (21) at their tip ends slidably engaged with guide paths (22) of the guide support means (19), When the cover body is rotated from the open position (P2) to the closed position (P1), the link arm (20) is pushed by the operating shaft, causing the engaging portion (21) to move forward along the guide path (22), thereby taking a folded position (Q1) along the side frame portion of the opening, When the lid body is rotated from the closed position (P1) to the open position (P2), the engaging portion (21) is pulled by the operating shaft and moves backward along the guide path (22), thereby assuming an upright position (Q2), and the engaging portion (21) is dropped and fitted into a lock groove (23) connected to the end of the guide path, thereby assuming a fixed locked state (L), and the open position (P2) of the lid body is maintained in the fixed locked state. The release mechanism (24) is composed of an operating piece (25) that rotates the operating shaft, a shaft end (18a) of the operating shaft, and a shaft support hole (20a) of a link arm into which the shaft end is inserted, and is configured to transmit the rotation of the operating shaft (18) in the release direction (V) to the link arm (20) to rotate the link arm in the release direction (W) and bring the engaging portion, which is in the fixed lock state (L), into an unlocked state (K) by being pulled out of the lock groove, and an arm interlocking mechanism (27) is configured between the shaft end (18a) and the shaft support hole (20a), The arm interlocking mechanism (27) is configured such that, with respect to the rotation in the release direction transmitted from the link arm (20) to the shaft end (18a), when the link arm is rotated within the range of angle θc from the fixed lock state (L) to the unlocked state (K), the rotation of the link arm is not transmitted to the shaft end or the shaft end is rotated by an angle smaller than the angle θc. A hatch device for a scaffolding board.

3. The engaging portion (21) is formed by a pin that protrudes laterally from the tip end of the link arm (20), The guide path (22) of the guide support means (19) is formed by a slot having upper and lower edge portions (22a, 22b) that hold the engaging portion from above and below in a state in which the engaging portion is slidably inserted, and the lock groove (23) is formed by a recess recessed downward from the end of the slot, A hatch device for a scaffolding board as described in claim 2, characterized in that an upward movement regulating means (22c) is formed by extending the upper edge portion (22a) of the slot to a position above the locking groove (23), thereby limiting the upward movement of the engaging portion (21).

4. The operating piece (25) constituting the release mechanism (24) is composed of an operating lever having a shaft support hole (25a) at its base end, and the operating shaft (18) is inserted into the shaft support hole (25a). When the operating piece (25) is rotated in the release direction (U), the operating shaft (18) is rotated in the release direction (V) via an interlock delay mechanism (26) provided between the shaft support hole (25a) of the operating piece and the operating shaft (18), A hatch device for a scaffolding board as described in claim 1, 2 or 3, characterized in that the interlocking delay mechanism (28) is configured so that when the operating piece (25) is rotated in the release direction (U), the rotation of the operating piece is not transmitted to the operating shaft until the operating piece rotates beyond a predetermined angle θa.

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