JP7828161B2 - Hatch device for scaffolding boards - Google Patents

Description

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 position-maintaining mechanism for maintaining the lid in an upright, open position.

Conventionally, in temporary scaffolding where work floors are constructed in upper and lower levels using scaffolding boards, some of the scaffolding boards are provided with a hatch device equipped with 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 means of ascent or descent such as a ladder or staircase is installed facing the opening. This allows workers to move between the upper and lower floors by raising and lowering the means of ascent while the lid is in the open position, leaving the opening open.

Similar hatch devices are also installed on suspended scaffolding, which is constructed by suspending scaffolding boards with chains, etc., and are used for emergency evacuation and other purposes.

Such hatch devices normally close the opening with a lid to prevent workers from falling, but for the above-mentioned purposes, 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.

Patent No. 3820360 Patent No. 5978148

It is desirable that the lid of the hatch device be 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.

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 retention mechanism to keep the lid body in the open position.

The position holding mechanism can be constructed using a variety of means, but in order to enable smooth rotation of the lid between the closed and open positions and to reliably and stably hold the lid in the open position, it is preferable to construct it using an operating shaft rotatably supported on the lid, 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 straddling the shaft ends at both ends of the operating shaft and the guide support means.

As a result, when the lid is rotated from the closed position to the open position, the tip of the link arm, 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 drops and fits into a locking groove provided at the end of the guide path, so the fixed, locked link arm can reliably hold the lid in the open position.

In the past, the release means for releasing the hold of the posture holding mechanism configured as described above was configured by providing an operating piece on the link arm, and the operator (user) lifting the link arm via the operating piece to release the fixed lock. However, because the lock on the link arm moves in the folding direction when the lid is rotated toward the closed position, it is dangerous and undesirable for the operator's fingers to approach the link arm.

Therefore, to release the lid from its open position, it is preferable to provide a release mechanism that is configured to rotate the operating shaft in the release direction by attaching an operating lever to the operating shaft, thereby rotating the link arm in the release direction and lifting the engaging portion out of the locking groove, thereby releasing the lock.

However, when unlocking the lid, the worker (user) may visually see the link arms in an upright position on both sides of the open lid, and may think that they can release the lock and return the lid to the closed position by rotating the link arms directly with their fingertips, as is done in conventional technology, and causing the engaging portions to escape from the locking grooves. 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 correct way.

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 to pivot in the closing direction under its own weight, and at the same time, the link arms move in the folding direction, posing a risk of trapping the worker's fingers.

The present invention aims to provide a hatch device that includes a position-holding mechanism that uses the link arm described above to reliably and stably hold the lid in the open position, while also ensuring operational safety when changing the lid from the open position to the closed position.

Therefore, the first means of the present invention is a hatch device that uses a lid to freely close and open an opening that connects the upper and lower spaces of a scaffolding board, 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 this 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 straddled between the shaft ends at both ends of the operating shaft and the left and right frame portions of the opening, and when the lid is rotated from the open position to the closed position, The lid is pushed forward by the operating shaft 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 backward by the operating shaft to assume an erect position. In the erect position, the engaging portions of the link arms are dropped and fitted into locking grooves provided on the left and right side frames to assume a fixed and locked state, and the open position of the lid is maintained in this fixed and locked state. The release mechanism transmits 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 lifts the link arm, which has been placed in the fixed and locked state, out of the locking groove to assume an unlocked state.

Furthermore, the second means of the present invention is a hatch device in which an opening communicating the upper and lower spaces of a scaffolding board is closed by a lid body in a manner that allows it to be opened and closed freely. The lid body is 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. The lid body is provided with a position holding mechanism that holds the lid body in the open position and a release mechanism that releases this holding. The position holding mechanism is provided with an operating shaft that is pivotally supported on the lid body and a lever that rotates freely on both the left and right sides of the opening. 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 guideway, thereby assuming an upright position. The engaging portion drops into and fits into a locking groove connected to the end of the guideway, thereby establishing a fixed, locked state, and the open position of the lid 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. The release mechanism 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. An arm interlocking mechanism is also configured between the shaft end and the shaft support hole. With regard to rotation in the release direction transmitted from the link arm to the shaft end, the arm interlocking mechanism is configured so that, when the link arm is rotated within an angle range 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 an angle smaller than the angle.

In a preferred embodiment, the engagement 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 edges that hold the engagement portion from above and below while it is slidably inserted, and the lock groove is formed by a recess recessed downward from the end of the slot, and the upper edge of the slot is extended to a position above the lock groove, thereby forming a means for restricting upward movement of the engagement portion.

In a further preferred embodiment, the operating piece that constitutes the release mechanism is composed of 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 interlock delay mechanism provided between the support hole of the operating piece and the operating shaft, and the interlock 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 has rotated beyond a predetermined angle.

According to the present invention, the lid body 8 is rotated between the folded position Q1 and the upright position Q by the position holding mechanism 16, with the pair of left and right link arms 20L, 20R guided by the pair of left and right guide support means 19L, 19R, resulting in smooth rotation. Furthermore, since 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, the open position P2 is reliably and stably held, allowing for safe operation.

Furthermore, with the configuration of the arm interlocking mechanism 27, even if an operator rotates one of the link arms 20L (20R) with their fingertips, thereby moving the engaging portion 21 upward from the fixed lock state L to the unlocked state K, with the link arms 20L, 20R holding the lid body 8 in the open position P2, the other link arm 20R (20L) remains in the fixed lock state L and holds the lid body 8 in the open position P2, preventing the risk of finger injury, etc.

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 body in a closed position to close the opening. 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. 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 a link arm and a guide means. FIG. 2 is a perspective view showing the cover in an open position. 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. 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. Regarding the operation of the posture holding mechanism and the release mechanism, (A) is a side view showing the operating method for changing the lid body from the open posture to the closed posture, and (B) is a side view showing the state in which the lid body is rotating from the open posture to the closed posture. FIG. 10 is a perspective view showing the relationship between the operating shaft, the operating piece, and the shaft support hole of the link arm in one embodiment of the release mechanism. 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. 1A is a side view showing the operation of the operating piece, the operating shaft, and the link arm when the operating piece is rotated in the release direction by a first step, and FIG. 1B is an enlarged view. 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. 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 operation of the operating piece, the operating shaft, and the link arm. 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. (A) is an oblique view showing the state in which the left and right link arms are fixed and locked in an upright position, (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.

A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

Figures 1 and 2 show an example of a scaffolding board 1 equipped with a hatch device. In the illustrated example, a scaffolding board for constructing temporary scaffolding is shown, but this is not limited to this and the scaffolding board may also be used for constructing suspended scaffolding.

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. In the example shown, 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.

The rectangular framework is located in the middle of the longitudinal direction and connects the girder side frames 2, 2 with an intermediate frame 4, thereby forming a first frame section 1A and a second frame section 1B.

The first frame 1A has floor plates 5 laid on it, 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 forming a hatch device 6. The lid 8 has a cover plate 9 made of the same material as the floor plates 5, and is configured so that when closed, the cover plate 9 is supported flush with the floor plates 5, thereby providing a work floor.

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

As shown in Figures 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. The frame is covered from above by the lid plate 9, which is inserted into the opening 7 to close the opening 7. In the closed state, the lid body 8 is placed on a mounting portion formed on the frame of the opening 7 and is supported from below.

Pivots 10 protruding from both ends of the lid base frame 8a that constitutes the framework of the lid body 8 are supported in pivot holes formed in the opening side frame portions 7c and 7d, so that the lid body 6 can rotate around the pivot 10 on the base end between a closed position P1 in which the opening 7 is closed and an open position P2 in which the lid body 6 tilts upright to open the opening 7. The relationship between the pivots 10 and the pivot holes may also 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.

(Closing locking mechanism)
A closure locking mechanism 11 is provided for releasably locking both ends of the lid tip frame 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 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.

The rod member 12 is supported so as to be able to slide freely 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 locking portion 12a.

The tail end of the rod member 12 is folded back into an approximately U shape to form the 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).

Although not shown in the figure, the tip locking portion 12a is formed with a guide tapered surface. 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 locking hole, causing the rod member 12 to slide against the spring 14, thereby retracting the tip locking portion 12a. As soon as the tip locking portion 12a faces the locking hole, it is protruded by the spring 14 and inserted and locked, creating an automatic locking mechanism.

To open the opening 7, the lid 9, which has been locked by the closure locking mechanism 11, can be moved from the closed position P1 to the open position P2 by inserting the operator's fingers into the window hole 15 and grasping the grip portions 12b, 12b of the pair of left and right rod members 12, 12. By moving the rod members 12, 12 against the spring 14 in a direction that brings the grip portions 12b, 12b closer to each other, the tip locking portion 12a is removed from the locking hole and the lock is released. As a result, the lid 8 can be rotated upright about the pivot 10 to take the open position P2.

(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.

The link arm 20 has its base end fitted with the shaft end 18a of the operating shaft 18, and an engagement portion 21 consisting of a pin protruding from the side of its tip end slidably engages with a guide path 22 provided in the guide support means 19. The guide path 22 is formed by a slot with upper and lower edges 22a, 22b that hold the engagement portion 21 from above and below when slidably inserted, and a lock groove 23 is formed by a recess recessed downward from the end of the slot. The upper edge 22a of the slot is extended to a position above the lock groove 23, and this extension constitutes an upward movement restriction means 22c that restricts the upward movement of the engagement portion 21.

Note that the guide support means 19L, 19R shown in the drawings have a pair of recesses at both ends of the guide path 21. This is to allow the same guide support means 19 to be used for both the left-hand and right-hand handles 19L, 19R. It should be understood that the recess at the tip of the guide path 22 (the side facing the opening base frame portion 7a) is functionally unnecessary.

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

As shown in Figure 6 (A), when the lid 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.

When the cover 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 engagement portion 21 to move backward along the guide path 22, while tilting in the upright direction from the engagement portion 21 toward the shaft end 18a.

Therefore, as shown in Figure 6 (C), when the lid body 8 reaches the open position P2, the link arm 20 is locked in place by the engagement 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 "locked state L"). As a result, the link arm 20 is in an upright position Q2, tilting up from the engagement portion 21 toward the shaft end 18a, and is prevented from moving forward or backward, maintaining the lid body 8 in the open position P2.

The posture holding mechanism 16 is configured to change the posture between the folded posture Q1 and the upright posture Q2 while guiding a pair of left and right link arms 20L, 20R with a pair of left and right guide support means 19L, 19R between the shaft end portions 18a, 18a at both ends of the operating shaft 18 journaled on the lid body 8 and the opening side frame portions 7c, 7d of the opening 7. Therefore, by holding the posture of the lid body 8 from both the left and right sides, the lid body 8 can be rotated smoothly, eliminating the risk of distortion or deformation of the pivot 10.

The lid 8 in the open position P2 is supported on both the left and right sides by link arms 20L, 20R, which are in the fixed lock state L. This means that it is held securely and stably in the open position P2. Even when subjected to external force, there is no risk of the lid 8 accidentally rotating toward the closed position P1, allowing for safe operation.

(Release mechanism)
In order to change the cover body 8 from the open position P2 to the closed position P1, a release mechanism 24 is provided which releases the fixed locked 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 which is 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.

As shown in Figure 7(A), when the link arm 20 is in the upright position Q2 and the operator rotates the operating piece 25 with their fingertip in the release direction U (the direction in which the operating lever is raised), 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, releasing the fixed lock state (hereinafter, this state is referred to as the "unlocked state K"). As a result, as shown in Figure 7(B), the engaging portion 21 of the link arm 20 can be moved forward along the guide path 21, while the lid body 8 can be rotated from the open position P2 to the closed position P1.

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

Now, regarding the mechanism for releasing the fixed lock of the link arm 20, to explain a comparative example to the present invention, if the shaft end 18a of the operating shaft 18 is directly connected (fixed integrally) to the base end of the link arm 20, and the operating shaft 18 is directly connected (fixed integrally) to the base end of the operating piece 25, there are the following dangers. The first danger is that when an operator touches the operating piece 25, the 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, which may cause the lid body 8 to accidentally rotate towards the closed position P1, resulting in the risk of physical injury to the operator. Furthermore, as a second risk, as mentioned above in relation to the problem to be solved by the invention, if an operator releases the locked state by rotating one of the link arms 20L(R) with their fingertips, the operating shaft 18 will rotate, and the other link arm 20R(L) will also simultaneously be released from the locked state. This will cause the lid 8 to rotate all at once towards the closed position P1, and there is a risk of injury to the operator's fingers or other parts of the body as the link arm 20 moves towards the folded position Q1.

(Interlocking delay mechanism and arm interlocking mechanism)
To prevent such a risk, the interlock delay mechanism 26 is configured so that when the operating piece 25 is rotated in the release direction, the rotation of the operating piece 25 is not transmitted to the operating shaft 18 until the operating piece 25 rotates 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 an operator rotates the operating piece 25 with his or her fingertip, the operator feels 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.

Furthermore, the arm interlocking mechanism 27 is configured such that, with respect to the path opposite to the path that transmits the rotation of the operating shaft 18 in the release direction to the link arm 20, i.e., the path that transmits the rotation of the link arm 20 in the release direction to the shaft end 18a of the operating shaft 18, when the link arm 20 is rotated in the release direction W within the range of angle θx that changes from the fixed locked state L to the unlocked state K, the rotation of the link arm 20 is not transmitted to the shaft end 18a, or if transmission is allowed, the shaft end 18a is only rotated an angle smaller than the angle θx.

Therefore, even if an operator rotates one of the left and right link arms 20L, 20R (29R) with their fingertips, moving the engaging portion 21 upward from the fixed lock state L to the unlocked state K, the other link arm 20R (L) remains in the fixed lock state L. This maintains the open position P2 of the lid body 8, preventing it from rotating toward the closed position P1.

In the illustrated embodiment, as shown in Figure 8, the operating shaft 18 is formed from a rod with a rectangular cross section along its entire length, and rectangular shaft support holes 25a and 20a similar in shape to the cross section of the rod are formed at the base end of the operating piece 25 and the base end of the link arm 20, respectively. The operating shaft 18 is loosely inserted into the shaft support hole 25a of the operating piece 25 to form the interlocking delay mechanism 26, and the shaft end 18a of the operating shaft 18 is loosely inserted into the shaft support hole 20a of the link arm 20 to form the arm interlocking mechanism 27.

In the embodiment shown in Figure 8, the cross-sectional shape of the operating shaft 18 is formed as a rectangle with 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 with 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 with one side Z1 and the other side Z2 (preferably a square with Z1 = Z2), with the lengths of the respective sides being configured such that X1 < Y1 < Z1 and X2 < Y2 < Z2.

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 pivot hole 25a of the operating piece 25 as shown in Figure 9(A), the rotation of the pivot hole 25a of the operating piece 25 is not immediately transmitted to the operating shaft 18. As shown in Figure 9(B), when the operating piece 25 rotates beyond a predetermined angle, the pivot hole 25a abuts and engages with sides Y and X or corners of the operating shaft 18, and when the operating piece 25 is rotated further, the operating shaft 18 rotates along with it.

The relationship between the shaft end 18a of the operating shaft 18 and the shaft support hole 20a of the link arm 20 is shown in Figures 9(C) and 9(D). Even if the shaft end 18a of the operating shaft 18 rotates in the release direction V as shown in Figure 9(D) in response to the rotation of the operating piece 25 described above from a state in which the shaft end 18a is loosely fitted in the center of the shaft support hole 29a as shown in Figure 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. As shown in Figure 9(D), when the shaft end 18a rotates beyond a predetermined angle, the sides X and Z or corners of the shaft end 18a and the shaft support hole 20a abut and engage. When the shaft end 18a rotates further, the link arm 20 rotates along with the shaft support hole 20a.

With regard to the above configuration, Figure 9 (E) shows the effect 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 standby position 0 to positions a, b, and c. When rotated from position b to position c, the link arm 20 is lifted by an angle θc, causing the engagement portion 20 to escape from the lock groove 22.

10, when the operating piece 25 rotates from the standby position 0 to the position a in the first stage, it rotates by an angle θa, but this rotation range is set as play for 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 sides Y and X or corners of the operating shaft 18 come into contact and engage with each other.

Continuing 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 support 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 support hole 20a of the link arm 20, and the link arm 20 does not rotate. In the second stage, it is only when the operating shaft 18 is rotated by angle θb that the operating shaft 18 and sides X and Z or corners of the pivot support hole 20a abut and engage.

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

Figures 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 their fingers, etc., rather than rotating the operating shaft 18 in the normal manner.

The arm interlocking mechanism 27 has one shaft end 18a inserted into the shaft support hole 20a of one of the left and right link arms 20L, 20R, and fixed in a predetermined position, and the other shaft end 18a inserted into the center of the shaft support hole 20a of the other link arm 20L. In the illustrated example, one shaft end 18a is fixed to one link arm 20R by threading a screw 28 into the shaft end surface. In the following description, one link arm 20R will be referred to as the fixed link arm 20R, and the other link arm 20L will be referred to as the floating link arm 20L.

As described above, the floating side link arm 20L is configured so that side X and side Z are greater than side 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 normal use, when the shaft end 18a is rotated to angle θb, side X or a corner abuts side Z or a corner of the shaft support hole 20a. When the shaft end 18a is further rotated to angle θc, the shaft support hole 20a of the link arm 20L rotates along with it, causing the link arm 20L to rotate by the same angle θc in the release direction W.

(Action when the fixed link arm is rotated)
Therefore, instead of the normal usage method, the following will explain the operation when the fixed link arm 20R of the pair of left and right link arms is rotated to an angle θc in the release direction W. When the link arm 20R is rotated to the angle θc, the engaging portion 20 moves upward from the fixed locked state L in which it is engaged with the lock groove 22 to the unlocked state L in which it is released from the engagement, but because 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.

When the fixed link arm 20R is rotated to angle θc, the operating shaft 18 fixed to it also rotates to angle θc. However, the floating link arm 20L only rotates through angle θx (θx = θc - θb), which is smaller than angle θc. Therefore, the floating link arm 20L maintains the locking portion 21 in the fixed lock state L.

(Action when the floating link arm is rotated)
Conversely, the operation when the floating link arm 20L of the pair of left and right link arms is rotated in the release direction W to an angle θc will be described.

When the floating link arm 20L rotates to angle θc, the engagement portion 20 of the arm 20L moves upward from a fixed locked state L in which it is engaged with the lock groove 22 to an unlocked state L in which it is released from the engagement. However, the operating shaft 10 only rotates by an angle θx (θx = θc - θb), which is smaller than angle θc. Therefore, the fixed link arm 20R does not rotate to angle θc and remains in the fixed locked state L. Incidentally, even in this case, the upward movement of the engagement portion 20 is restricted by the upward movement restriction means 22c, so the floating link arm 20L does not rotate beyond the angle θc.

(Another embodiment)
The arm interlocking mechanism 27 is configured by forming the side X of the shaft end portion 18a of the operating shaft 18 and the side Z of the shaft support hole 20a so that X<Z. In the floating side link arm 20L, the relationship between the rotation angle θb until the side X and the side Z or the corner abut each other and the rotation angle θc for moving the engaging portion 21 of the link arm 20L upward from the fixed locked state L to the unlocked state K can be formed so that θb>θc.

In this case, by rotating the fixed-side link arm R in the release direction W to an angle θc, even if the operating shaft 18 is rotated to the same angle θc, the rotation of the operating shaft 18 is not transmitted to the shaft support hole 20a of the floating-side link arm 20L, and therefore the floating-side link arm 20L does not rotate.

Conversely, even if the floating link arm L rotates to an angle θc in the release direction W, the rotation of the floating link arm 20L is not transmitted to the operating shaft 18, and therefore the fixed link arm R does not rotate.

With the arm interlocking mechanism 27 configured as described above, even if the link arms 20L, 20R holding the lid 8 in the open position P2 are rotated by the operator with their fingertips, rather than using the correct method, to move the engaging portion 21 upward from the fixed lock state L to the unlocked state K, the other link arm 20R (20L) will remain in the fixed lock state L, so the lid 8 can be maintained in the open position P2, preventing the risk of injury to the operator's fingers.

(Yet another embodiment)
In the illustrated embodiment, the arm interlocking mechanism 27 is configured by forming the cross-sectional shape of the operating shaft 18 (shaft end 18a) and the hole shape of the shaft support hole 20a as rectangular, with side X and side Z being X<Z. However, the present invention is not limited to this configuration. For example, the arm interlocking mechanism 27 may be configured by providing a rib extending in the axial direction on the surface of the operating shaft 18, which is a rod having a substantially circular cross section, and by providing a groove in the shaft support hole 20a of the link arm 20 into which the operating shaft 18 is inserted, into which the rib is loosely inserted, thereby forming a space between the rib and the groove side surface with respect to rotation in the release direction. In this case, a relationship can be formed between the rib of the operating shaft 18 and the groove in the shaft support hole 20a such that when one of them is rotated to angle θc, the other rotates only through angle θx (θx = θc - θb), which is smaller than angle θc, thereby achieving the same effects as those of the above embodiment.

1 Scaffolding board 1A First frame portion 1B Second frame portion 2 Girder side frame 3 Gable side frame 4 Intermediate frame 5 Floor board 6 Hatch device 7 Opening 7a Opening base frame portion 7b Opening tip frame portion 7c, 7d Opening both side frame portion 8 Lid body 8a Lid base frame portion 8b Lid tip frame portion 8c, 8d Lid both side frame portion 9 Lid plate 10 Pivot 11 Closing locking mechanism 12 Rod member 12a Tip locking portion 12b Grip portion 13 Support fitting 14 Spring 15 Window hole 16 Posture holding mechanism 17 Bracket 18 Operating shaft 18a Shaft end portion 19L, 19R Guide support means 20L, 20R Link arm 20a Shaft support hole 21 Engagement portion 22 Guide path 22a Upper edge portion 22b Lower edge portion 22c Upward movement regulating means 23 Lock groove 24 Release mechanism 25 Operating piece 25a Shaft support hole 26 Interlocking delay mechanism 27 Arm interlocking mechanism 28 Screw P1 Closed position P2 Open position Q1 Folded position Q2 Standing position
U, V, W Release direction L Fixed locked state K Unlocked state

Claims (4)

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). 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 so that, with regard 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. 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). 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.