Ladder inside the shaft

Abstract

To reduce the time and labor required to install a ladder.SOLUTION: In a ladder 1 for use in a vertical shaft, multiple ladder members 7, including two supports 5 arranged in the vertical direction and a plurality of steps 6 installed at an appropriate interval in the vertical direction between the supports 5, are arranged continuously in the vertical direction in a vertical shaft 3 in which a liner plate 2 is installed on a shaft wall. Each of the ladder members 7 has a bent portion at the upper end of a portion extending upward from the supports 5, and is provided with a hook portion 11 which allows the ladder members 7 to be connected in the vertical direction by hooking the bent portion to the lowermost step 6 of the ladder member 7 on the upper stage side, and is also provided with a mounting fitting 12 which extends from the supports 5 to the liner plate 2 side and has at the tip thereof a fixing portion 13 which can be fixed to a connecting bolt 2a of the liner plate 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a shaft ladder arranged along the vertical direction for workers to ascend and descend in a shaft with a liner plate installed on the shaft wall.

Background Art

[0002] Conventionally, in deep foundation work such as bridge foundation work in urban areas and mountainous regions, a deep foundation method has been used. In this deep foundation method, while retaining the soil on the shaft wall with a liner plate or the like, a shaft is constructed by excavating with an excavating machine such as manual labor or a small backhoe, and when reaching a predetermined bearing ground, reinforcement is arranged inside and concrete is placed to construct a foundation. The liner plate has flanges provided on four sides around a steel corrugated plate, and a plurality of apertures for inserting connecting bolts are formed in the flanges.

[0003] On the inner peripheral surface of the liner plate, a ladder is provided along the vertical direction so that workers can ascend and descend in the shaft.

[0004] As a fixing structure of the ladder, it is often fixed to the connecting bolts of the liner plate. For example, in Patent Document 1 below, the ladder part has a step and a support part for supporting the step, the base end of the support part is bent to form a contact part with the flange of the liner plate, a hole for passing a bolt is formed in the contact part, and the bolt is passed through this hole and tightened to attach the ladder part to the flange. The ladder part described in this Patent Document 1 is attached to the flanges of the liner plates adjacent to each other in the vertical direction, respectively, and two attached vertically form a pair.

[0005] Also, in Patent Document 2 below, two shaft rods arranged along the vertical direction in the shaft are arranged at a predetermined interval, and a plurality of cross rods are provided at appropriate intervals along the longitudinal direction between the two shaft rods, and mounting brackets locked to the inner peripheral surface of the shaft are respectively projected at both ends of the two shaft rods to form a ladder member. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Utility Model Publication No. 6-47599 [Patent Document 2] Japanese Patent Application Publication No. 10-25888 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in the ladder described in Patent Document 1, each ladder section is constructed with support parts formed at both ends of a single step. Therefore, it is necessary to install as many ladder sections as there are steps, which requires a great deal of time and effort to install the ladder.

[0008] Furthermore, in the ladder described in Patent Document 2, two mounting brackets extend from the upper and lower parts of each ladder member, and the tip of each mounting bracket is fixed to the connecting bolt of the liner plate. As a result, a total of four bolt fastening operations are required for each ladder member, which requires a great deal of time and effort to install the ladder.

[0009] Therefore, the main objective of the present invention is to provide a shaft ladder that reduces the time and effort required for ladder installation. [Means for solving the problem]

[0010] To solve the aforementioned problems, the present invention according to claim 1 provides a vertical shaft ladder in which a plurality of ladder members are arranged in a vertical direction, each ladder member comprising two support columns arranged vertically and a plurality of steps erected between the support columns at appropriate vertical intervals, the vertical shaft ladder having a liner plate installed on the shaft wall, The aforementioned ladder member has a bent portion at the upper end of the part that extends upward from the support column, and is equipped with a hook portion that allows the ladder members to be connected vertically by hooking this bent portion onto the lowest step of the upper ladder member, The mounting bracket extends from the support column toward the liner plate and has a fixing portion formed at its tip that can be fixed to the connecting bolt of the liner plate. Occasionally, The hook portion extends parallel to the support column, passing through the corner between the support column and the uppermost step of the ladder member to which the hook portion is provided, and is positioned at an angle such that the tip of the bent portion at its upper end faces towards the center in the width direction of the ladder member. A shaft ladder characterized by the following is provided.

[0011] In the invention described in claim 1 above, a vertical shaft ladder is formed by arranging a plurality of ladder members, each having a plurality of steps between support columns, in a vertical direction, wherein the ladder members have a bent portion at the upper end of the portion extending upward from the support column, and the ladder members are provided with a hook portion that allows them to be connected vertically by hooking the bent portion onto the lowest step of the upper ladder member, and a mounting bracket that extends from the support column toward the liner plate and has a fixing portion formed at its tip that can be fixed to the connecting bolt of the liner plate.

[0012] In this way, by hooking the hook portion onto the step of the upper ladder member, the upper end of the ladder member is connected to the upper ladder member, and by fixing the fixing portion provided at the tip of the mounting bracket to the connecting bolt of the liner plate, the ladder member is fixed to the liner plate. As a result, fixing the ladder member is completed simply by fixing the two connecting bolts at the tip of the mounting bracket, and the time and effort required for ladder installation work is greatly reduced.

[0013] Also, The hook portion extends parallel to the support column, passing through the corner between the support column and the uppermost step of the ladder member to which the hook portion is provided, and is positioned at an angle such that the tip of the bent portion at its upper end faces towards the center in the width direction of the ladder member. Therefore, The aforementioned hook portion is designed to be easily attached to the step of the upper ladder component. Naru At the same time, it increases stability after locking, enhancing safety. It will become like that.

[0014] Claim 2 As the invention according to claim

[0015] The above claim 2 In the invention described above, in order to be able to fix the mounting bracket at an arbitrary position with respect to the column, a clamp is provided at the end of the mounting bracket on the connecting side with the column, and it can be fixed to the column by this clamp.

[0016] Claim 3 As the invention according to claim

[0017] The above claim 3 The invention described above is the first exemplary form of the mounting bracket, in which the fixing portion is provided at the tip of a support member that curves upward or downward from the column. By curving the support member, even when a reinforcing ring is provided on the liner plate, the mounting bracket can be installed without interfering with this reinforcing ring.

[0018] Claim0000085As the invention according to claim

[0019] [[ID=​​​​​​​​As described in detail above, according to the present invention, in the shaft ladder, the time and labor required for the installation work of the ladder can be significantly reduced.

Brief Description of the Drawings

[0021] [Figure 1] The shaft ladder 1 according to the present invention is shown, (A) is a side view, and (B) is a front view. [Figure 2] The ladder member 7 is shown, (A) is a front view, (B) is a top view, and (C) is a view taken in the direction of the arrow C-C of (A). [Figure 3] (A) and (B) are front views showing the connection method of the ladder member 7. [Figure 4] The ladder member 7 according to the modified example is shown,(A) is a front view, (B) is a top view, and (C) is a view taken in the direction of the arrow C-C of (A). [Figure 5] (A) is an enlarged view of the connecting portion of the ladder member 7, (B) is an enlarged view taken in the direction of the arrow B-B of (A), and (C) is an enlarged view taken in the direction of the arrow C-C of (A). [Figure 6] The mounting bracket 12 according to the first embodiment is shown, (A) is a front view, and (B) is a top view. [Figure 7] The mounting bracket 12 according to the modified example is shown, (A) is a front view, and (B) is a top view. [Figure 8] It is a side view showing the fixing method (Part 1) by the mounting bracket 12. [Figure 9] It is a side view showing the fixing method (Part 2) by the mounting bracket 12. [Figure 10] The mounting bracket 12 according to the second embodiment is shown, (A) is a front view, and (B) is a top view. [Figure 11] It is a side view showing the fixing method (Part 3) by the mounting bracket 12. [Figure 12] The pithead ladder member 8 is shown, (A) is a front view, (B) is a top view, and (C) is a side view. <> [Figure 13] The handrail 9 is shown, (A) is a side view, (B) is a top view, (C) is a front view, and (D) is a view taken in the direction of the arrow D-D of (A). [Figure 14]This is a front view showing the tunnel entrance ladder member 8 with the handrail 9 installed. [Figure 15] This is a top view showing the backrest 10. [Modes for carrying out the invention]

[0022] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0023] As shown in Figure 1, the shaft ladder 1 according to the present invention is a ladder for workers to ascend and descend, arranged vertically within a shaft 3 in which a plurality of liner plates 2 are installed along the circumferential and vertical directions of the shaft wall. The shaft ladder 1 is constructed by arranging a plurality of ladder members 7 in a continuous vertical direction, each ladder member 7 having two support columns 5, 5 arranged parallel to each other with a predetermined spacing width, and a plurality of steps 6 installed between the support columns 5, 5 at appropriate vertical intervals. Furthermore, a shaft entrance ladder member 8 with handrails 9 on both sides is provided at the shaft entrance end of the shaft ladder 1. In addition, a plurality of backrests 10 are arranged on the shaft ladder 1 at appropriate vertical intervals.

[0024] As shown in detail in Figure 2, the ladder member 7 extends upward from the upper end of the support column 5, and its upper end is bent in a U-shape. This bent portion is hooked onto the lowest step 6 of the upper ladder member 7, thereby enabling the ladder members 7 to be connected vertically (see Figure 3). Reference numeral 5a in Figure 2 indicates a cover that closes the openings at the upper and lower ends of the support column 5, which is made of tubular material.

[0025] Furthermore, as shown in Figure 1, the ladder member 7 is equipped with a mounting bracket 12 that extends from the support column 5 towards the liner plate 2 and has a fixing portion 13 formed at its tip that can be fixed to the connecting bolt 2a of the liner plate 2.

[0026] The following explains it in more detail: The ladder member 7 is made of metal such as iron or aluminum. The support column 5 is a longitudinal member that is long in the vertical direction and made of shaped steel materials such as circular pipes, square pipes, or angle steel.

[0027] Step 6 consists of a solid, elongated rod with a circular, semicircular, or polygonal cross-section, and is fixed to the support column 5 by inserting both ends into openings provided in the support column 5 and welding the connecting parts. Multiple Step 6s are provided at predetermined intervals in the vertical direction, starting from a position a predetermined distance downward from the upper end of the support column 5.

[0028] The steps 6 are arranged at approximately constant vertical intervals along the entire length of the shaft ladder 1, preferably at intervals of about 300 to 400 mm. The length of the hook portion 11 is adjusted so that the interval between adjacent steps 6 is constant even between the ladder members 7, 7 that are connected in the vertical direction.

[0029] The ladder member 7 shown in Figure 2 has a height (total length) of approximately 2m, with six steps 6 arranged between the support columns 5, 5. As a variation, as shown in Figure 4, the height (total length) of the ladder member 7 may be approximately 1m, with three steps 6 arranged between the support columns 5, 5. It is preferable to increase the height of the ladder member 7 so that a longer ladder can be installed in a single installation operation, further reducing the time and effort required for installation. However, if it is made too long, the load on the mounting bracket 12 will become excessive, making it more likely for problems such as damage to the mounting bracket 12 or improper fixing to occur. Therefore, it is best to keep it to about 2m as shown in Figure 2. The ladder member 7 of approximately 1m shown in Figure 4 is particularly suitable when installing a ladder in an odd-sized section such as the bottom of a tunnel.

[0030] The hook portion 11 is made of a solid, elongated rod with a circular or polygonal cross-section, and as shown in Figure 2(C), it has a base portion 11a that connects to the outer surface of the support column 5 and extends parallel to the support column 5, and an upwardly extending portion 11b that protrudes upward from the upper end of the support column 5. The upper end of the upwardly extending portion 11b is bent into an inverted U-shape, inverted V-shape, or U-shape, thereby forming a bent portion that can be hooked onto the step 6 of the upper ladder member 7. The portion of the base portion 11a that connects to the support column 5 and is arranged parallel to it is welded and fixed to the support column 5 continuously or intermittently over almost its entire length.

[0031] As shown in Figure 5, the base end 11a of the hook portion 11, which is fixed to the support column 5, passes through the corner between the support column 5 and the uppermost step 6 of the ladder member 7 to which the hook portion 11 is provided, and is positioned parallel to the support column 5 in terms of its axial direction. Furthermore, the upper extension portion 11b of the hook portion 11 is provided at an angle such that the tip of the bent portion at the upper end faces the center in the width direction of the ladder member 7. The fact that the tip of the bent portion at the upper end is provided at an angle so that it faces the center in the width direction of the ladder member 7 means that, as shown in Figures 2(B) and 4(B), when the ladder member 7 is viewed from above, the distance between the left and right hook portions 11 that protrude from the support column 5 towards the liner plate 2 gradually decreases as you move towards the protruding side.

[0032] In the shaft ladder 1 according to the present invention, the base end 11a of the hook portion 11 is positioned parallel to the axial direction of the support column 5 at a location that passes through the corner between the support column 5 and the step 6. As shown in Figure 5, when the ladder member 7 is hooked onto the upper ladder member 7, the upwardly extending portions 11b of the left and right hook portions 11 extending from the lower ladder member 7 engage with the corner between the support column 5 of the upper ladder member 7 and the lowest step 6, respectively, thereby preventing rattling between the upper and lower ladder member 7. Furthermore, since the tip of the bent portion at the upper end of the hook portion 11 is angled to face the center in the width direction of the ladder member 7, when hooking the upper ladder member 7 onto the step 6, the hook portion 11 can be smoothly inserted between the left and right support columns 5, 5 of the upper ladder member 7, making it easier to hook the upper ladder member 7 onto the step 6. Furthermore, the stability when the hook portion 11 is hooked onto the step 6 is increased, thereby enhancing safety. Specifically, if the tip of the hook is provided to protrude perpendicularly from the support column 5, as shown in Figure 5(B), the outer widthwise portion of the hook portion 11, which is made of a round bar, and the inner widthwise portion of the support column 5, which is made of a circular pipe, overlap slightly to form an overlap portion W. In this case, the hook portion 11 comes into contact with the support column 5 of the upper ladder member 7, resulting in poor stability. However, as in the present invention, if the tip of the hook is provided at an angle so that it faces the center in the widthwise direction, when the hook portion 11 is hooked onto the step 6, collision between the hook portion 11 and the support column 5 of the upper ladder member 7 can be avoided, and it can be hooked securely without rattling.

[0033] As described above, the base end of the hook portion 11 is fixed to the support column 5 for almost its entire length, but it is preferable that the length of this fixed portion (the length of the lower end of the hook portion 11 that is connected to the support column 5 and arranged parallel to it) be the length that extends from the upper end of the support column 5 downwards from the uppermost step 6 of the ladder member 7. At this time, as shown in the side views of the ladder member 7 in Figures 2(C) and 4(C), since the step 6 is located on the vertical centerline (axis) of the support column 5, the base end 11a of the hook portion 11 is positioned at a location offset from the step 6 towards the liner plate 2 side (shaft wall side) or the opposite side (center side of the shaft 3), such that the central axis of the support column 5 and the central axis of the base end of the hook portion 11 are approximately parallel. In this case, as shown in Figures 2(C) and 4(C), it is preferable to position the base end 11a of the hook portion 11 on the opposite side of the liner plate 2 (towards the center of the shaft 3) relative to the step 6, as this makes it easier for the centerline with the upper ladder member 7 to coincide, and makes it easier for the multiple connected ladder members 7 to be positioned straight in the vertical direction.

[0034] When the hook portion 11 is hooked onto the step 6 of the upper ladder member 7, at least the portion of the hook portion 11 that comes into contact with the step 6 may be covered with non-slip rubber to prevent slippage with the step 6 and to improve the fit between the two.

[0035] Next, the mounting bracket 12 will be described. The mounting bracket 12 is a stay for fixing each support column 5 of the ladder member 7 to the liner plate 2. One end of the mounting bracket 12 is fixed to the support column 5 of the ladder member 7, and the fixing portion 13 at the other end is fixed to the connecting bolt 2a that connects the liner plates 2 together. The position in which the mounting bracket 12 is fixed to the support column 5 is arbitrary, but since the upper end of the ladder member 7 is hooked onto the step 6 of the upper ladder member 7 by the hook portion 11, it is preferable that the position be below the vertical center of the ladder member 7 from the viewpoint of increasing the stability of the ladder member 7 when it is installed.

[0036] The mounting bracket 12 has a clamp 14 at one end of a support member of a predetermined shape (described later) for connecting to the support column 5, and a fixing part 13 at the other end that can be fixed to the connecting bolt 2a of the liner plate 2. A general-purpose single-pipe clamp is used as the clamp 14. The single-pipe clamp is a component that has been conventionally used at temporary scaffolding assembly sites, and is configured to be fixed to a pipe by clamping the outer circumference of the pipe. The fixing part 13 has an opening 15 through which the connecting bolt 2a can be inserted.

[0037] As a support member, each end of which is provided with the clamp 14 or fixing part 13, the following first or second embodiment can be used. The first embodiment of the mounting bracket 12 is configured such that, as shown in Figures 6 and 7, the fixing part 13 or clamp 14 is provided at each end of a support member 16 that curves upward or downward from the support column 5. The support member 16 according to the first embodiment is a curved, elongated rod-shaped member, and specifically, a solid round bar or PC steel bar with a circular cross-section is preferably used. The support member 16 is formed in a substantially semi-circular shape with a predetermined radius, and the tangential directions of one end where the clamp 14 is provided and the other end where the fixing part 13 is provided are substantially perpendicular to each other. The support member 16 may be formed only in a roughly semicircular shape, as shown in Figure 6, depending on the distance between the liner plate 2 and the shaft ladder 1, or it may be formed with a roughly semicircular curved portion 16a and a straight portion 16b that extends tangentially and is continuous with the end of the curved portion 16a on the side where the clamp 14 is provided, as shown in Figure 7.

[0038] To support the ladder member 7 with the mounting bracket 12 according to the first embodiment, as shown in Figures 8 and 9, the connecting bolt 2a of the liner plate 2 is inserted through the opening 15 of the fixing part 13, and then inserted through the opening for inserting the connecting bolt of the liner plate 2 and fixed with a nut, thereby fixing the fixing part 13 of the mounting bracket 12 to the liner plate 2 and fixing the clamp 14 to the support column 5. In the mounting bracket 12 according to the first embodiment, since the support member 16 is curved in a predetermined shape, even when the step 6 is positioned at approximately the same height as the connecting part of the liner plate 2, as shown in Figure 8, the clamp 14 can be fixed in a position where the step 6 is not provided. Also, as shown in Figure 9, when a reinforcing ring 20 is provided on the liner plate 2, if the support member 16 is straight, it will interfere with the reinforcing ring 20, and the mounting bracket 12 cannot be attached without modifying the reinforcing ring 20. However, since the support member 16 is curved in a predetermined shape, the mounting bracket 12 can be installed without interfering with the reinforcing ring 20. From the viewpoint of preventing interference with the reinforcing ring 20, the radius of the curved portion of the support member 16 can be appropriately adjusted according to the size of the H-shaped steel of the reinforcing ring 20, but it is preferable to set it to 150 to 250 mm, and especially to about 200 mm. The direction in which the support member 16 curves may be such that it curves upward from the support column 5, as shown in Figure 8, or it may be such that it curves downward from the support column 5, as shown in Figure 9.

[0039] As a second example of the mounting bracket 12, as shown in Figure 10, the fixing portion 13 or clamp 14 is provided at each end of a support member 17 that extends straight from the support column 5 in a nearly vertical direction toward the liner plate 2. The support member 17 in the second example is a straight member with a certain degree of bending rigidity, and specifically, shaped steel materials such as angle steel or channel steel are preferably used. The fixing portion 13 is formed at one end of the support member 17 by forming an opening 15 through which the connecting bolt of the liner plate 2 can be inserted.

[0040] To support the ladder member 7 with the mounting bracket 12 according to the second embodiment, as shown in Figure 11, the connecting bolt 2a of the liner plate 2 is inserted through the opening 15 of the fixing part 13, and then inserted through the opening for inserting the connecting bolt of the liner plate 2 and fixed with a nut, thereby fixing the fixing part 13 of the mounting bracket 12 to the liner plate 2 and fixing the clamp 14 to the support column 5. In the mounting bracket 12 according to the second embodiment, since the support member 17 extends straight, it is preferable to use it in places where a reinforcing ring cannot be provided.

[0041] In the shaft ladder 1 according to the present invention, as shown in Figure 1, a shaft entrance ladder member 8 is positioned at the shaft entrance end of the shaft 3, and handrails 9 are provided on both sides thereof.

[0042] As shown in Figure 12, the aforementioned tunnel entrance ladder member 8 comprises two support columns 18, 18 made of cylindrical pipes or the like, which are arranged parallel to each other along the vertical direction and with a predetermined spacing width, and a plurality of steps 6 that are installed between the support columns 18, 18 at appropriate intervals in the vertical direction. At the upper end of each support column 18, grooves 18a are provided, formed to a predetermined depth from the upper edge at positions opposite each other in the diametrical direction.

[0043] As shown in Figure 13, the handrail 9 consists of a support column 9a, a handrail member 9b provided on the upper part of the support column 9a, and projections 9c, 9c that protrude in the diametrical direction below the handrail member 9b and at positions opposite to the diametrical direction of the support column 9a.

[0044] To attach the handrail 9 to the tunnel entrance ladder member 8, as shown in Figure 14, the support post 9a of the handrail 9 is inserted into the upper end opening of the support post 18 of the tunnel entrance ladder member 8, and the projection 9c of the handrail 9 is fitted into the groove 18a of the tunnel entrance ladder member 8. This allows the handrail 9 to be attached to the support post 9a without rotation.

[0045] To fix the tunnel entrance ladder member 8 to which the handrail 9 is attached to the liner plate 2, the upper and lower parts of each support column 18 of the tunnel entrance ladder member 8 are fixed to the liner plate 2 by the mounting bracket 12, as shown in Figure 1.

[0046] Next, the backrests 10, which are provided at appropriate intervals in the vertical direction of the shaft ladder 1, consist of a backrest body 10a made of an arc-shaped strip or plate material and clamps 10b provided at both ends thereof, as shown in Figure 15. By fixing the left and right clamps 10b to the left and right support columns 5 of the ladder member 7, safety is ensured when workers ascend and descend the shaft ladder 1.

[0047] Although not shown in the diagram, the ladder 1 inside the shaft has landings at regular intervals to ensure safety in the event of a fall, and the ladder is assembled with its position changed accordingly. [Explanation of Symbols]

[0048] 1…Ladder inside the shaft, 2…Liner plate, 3…Shaft, 5…Support column, 6…Step, 7…Ladder component, 8…Ladder component at the shaft entrance, 9…Handrail, 10…Backrest, 11…Hook section, 12…Mounting bracket, 13…Fixing section, 14…Clamp, 15…Opening, 16-17…Support members

Claims

1. A vertical shaft ladder is constructed by arranging multiple ladder members in a series in the vertical direction, each ladder member comprising two support columns arranged vertically and a plurality of steps erected between the support columns at appropriate vertical intervals, within a vertical shaft where liner plates are installed on the shaft wall. The aforementioned ladder member has a bent portion at the upper end of the part that extends upward from the support column, and is equipped with a hook portion that allows the ladder members to be connected vertically by hooking this bent portion onto the lowest step of the upper ladder member, The mounting bracket extends from the support column toward the liner plate and has a fixing portion formed at its tip that can be fixed to the connecting bolt of the liner plate. The shaft ladder is characterized in that the hook portion passes through the corner between the support column and the uppermost step of the ladder member to which the hook portion is provided, extends parallel to the support column, and the tip of the bent portion at the upper end is provided at an angle so as to face the center in the width direction of the ladder member.

2. The shaft ladder according to claim 1, wherein the mounting bracket is provided with a clamp for fixing to the support column.

3. The mounting bracket is provided with the fixing portion at the tip of a support member that curves upward or downward from the support column, as described in claim 1.

4. The shaft ladder according to claim 1, wherein the mounting bracket has the fixing portion formed at the tip of a support member that extends almost vertically and straight from the support column.

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