JP4551907B2 - Receiving frame for a lid for an underground structure provided with a fall prevention ladder and a fall prevention ladder - Google Patents

Description

  The present invention relates to a fall-preventing ladder that is mounted so as to be raised and lowered with respect to a receiving frame for an underground structure lid, and a receiving frame for an underground structure lid that includes the falling-preventing ladder. The "underground structure lid" as used in the present invention means a large iron lid, a manhole lid, a sewage gutter lid, an electric power / communication lid that closes an opening through an underground structure, underground structure facility, etc. in the sewer. Opening and closing common gutter iron lid, power transmission iron lid, power distribution iron lid, buried conduit under the road surface in waterworks and gas piping and its associated equipment and the ground to protect underground facilities equipment and underground cables etc. A fire hydrant lid, a water control valve lid, a gate valve lid, an air valve lid, a gas pipe lid, a water meter lid, etc., that function as a door.

  Conventionally, there is an invention disclosed in, for example, FIG. 19 as a ladder of this type of underground structure lid. This manhole with an auxiliary ladder is a receiving piece in which a base portion of a ladder 103 is pivotably supported on a pair of pivoting pieces 102 provided on the inner peripheral surface of the receiving frame 101 so that the top of the ladder 103 is formed on the inner periphery of the receiving frame 101. It is configured to be supported by 104, and is used as a fall-preventing lid in a lying state, and can be used as a ladder by standing and fixing (see Patent Document 1).

Japanese Utility Model Publication No. 60-33162 (pages 2 to 3, Fig. 1)

  However, in the above invention, when lifting pressure is generated in the manhole due to a temporary increase in rainfall due to heavy rain, the lock provided on the lid body may come off the receiving frame and open the lid. .

  In this case, since the ladder 103 is simply laid down and the tip is only supported by the receiving piece 104 on the inner peripheral surface of the receiving frame 101, the lid 103 pivots on the pivoting piece 102 of the receiving frame 101 when the lid body is opened. With the base of the supported ladder 103 as a fulcrum, the lid main body is opened at the same time as the lid is opened, and a passerby may fall into the manhole.

  The present invention was devised in view of the above points, and even if the lid body should be opened by lifting pressure, the fall prevention ladder and the underground structure provided with the fall prevention ladder that can maintain a lying state An object of the present invention is to provide a receiving frame for an object lid.

In order to achieve the above object, the fall prevention ladder according to the present invention is mounted so as to be able to undulate with respect to a mounting portion formed on the inner periphery of the receiving frame, and supports the tip of which is opposed in a lying state. And a ladder main body connected to and supported by the fixing member, and a side wall of the ladder main body is slidable on the base end side of the ladder main body. And a sliding member that is pressed against the fixing member by an urging member is provided, and a vertical portion that rises upward is formed in the fixing member, and a locking groove portion is opened in the vertical portion. The sliding member is formed with a fitting portion that can be fitted into the locking groove portion, and the fitting portion has a tapered side at one end and a tapered portion for unlocking on the other side. It is slidably mounted in the direction In a state where the fitting portion is fitted in the locking groove portion, the one end side surface is in a tapered shape and the opposite surface of the locking groove portion is in contact, and the other end side surface is only the unlocking taper portion. It is set as the structure which can hold | maintain the standing state of a ladder main body by contact | abutting the surface which the said locking groove part opposes .
Further, the fall prevention ladder according to the present invention is mounted so as to be able to undulate with respect to the mounting portion formed on the inner periphery of the receiving frame, and the tip is supported by the opposing supporting portion in a lying state, the mounting And a ladder main body coupled to and supported by the fixing member, and a base end side of the ladder main body is slidably inserted into the side wall of the ladder main body and biased. A sliding member that is pressed against the fixing member by a member is provided, and a vertical portion that rises upward is formed in the fixing member, and a locking groove portion is opened in the vertical portion, and the sliding member A fitting portion that can be fitted into the locking groove portion is formed, and in a state where the ladder main body is raised, the fitting portion is fitted into the locking groove portion, and the standing state of the ladder main body can be maintained. On the base end side of the ladder main body, the ladder main body is A long hole portion that is pivotably and slidably supported while resisting the urging force is formed, and when lying down, the ladder body is moved to the tip side by the length of the long hole portion, and is raised. In the state which is made to have it, it is set as the structure provided with the means to maintain the said ladder main body in the state which moved to the base end side by the length of the said long hole part.
Further, the fall prevention ladder according to the present invention is mounted so as to be able to undulate with respect to the mounting portion formed on the inner periphery of the receiving frame, and the tip is supported by the opposing supporting portion in a lying state, and the mounting And a ladder main body coupled to and supported by the fixing member, and a base end side of the ladder main body is slidably inserted into the side wall of the ladder main body and biased. A sliding member that is pressed against the fixing member by a member is provided, and a vertical portion that rises upward is formed in the fixing member, and a locking groove portion is opened in the vertical portion, and the sliding member A fitting portion that can be fitted into the engaging groove portion is formed, and the fitting portion is formed such that one end side surface thereof is tapered and the other end side surface is attached with a lock releasing taper portion that is slidable in the vertical direction. And the fitting portion is the locking groove portion. In the inserted state, the one end side surface has a tapered portion in contact with the opposing surface of the locking groove portion, and the other end side surface has only the unlocking tapered portion facing the locking groove portion. The ladder main body can be maintained in an upright state by abutting against the ladder main body, and the ladder main body is pivotally supported on the base end side of the ladder main body so as to be rotatable and slidable against the biasing force of the biasing member. In the state where the ladder main body is moved to the front end side by the length of the long hole portion and is standing, the ladder main body is set to the length of the long hole portion. Means are provided for maintaining the state of moving to the proximal end side by that amount.

Here, the insertion portion is formed such that one end side surface is tapered and the other end side surface is attached with a taper portion for unlocking so as to be slidable in the vertical direction, and the insertion portion is inserted into the locking groove portion. The side of one end of the ladder is in contact with the opposing surface of the locking groove, and the other side of the other side is in contact with the opposing surface of the locking groove, so that the ladder body is raised. Since the state can be maintained, the ladder body can be held in an upright state without rattling, and the fitting portion can be smoothly removed from the locking groove portion.
In addition, with the ladder body upright, the fitting part fits into the locking groove, so that the ladder body can be kept upright, and the ladder body is biased by the biasing member on the base end side of the ladder body. A long hole that is pivotally and slidably supported while being resisted is formed, and when lying down, the ladder body is moved to the tip side by the length of the long hole and is standing In this case, means for maintaining the ladder main body in the state of being moved to the base end side by the length of the long hole portion enables the ladder main body to fall without contacting the receiving frame, and at the time of falling down the ladder The main body and the receiving frame can be automatically engaged.

  According to the fall-preventing ladder according to the present invention, the sliding member is provided on the base end side of the ladder body, and since this sliding member is constantly pressed against the fixed member by the biasing force of the biasing member, Even if the pressure rises inside the manhole due to an increase in rainfall, etc., and the lid body opens, the fall prevention ladder is maintained in a lying state, ensuring that passersby fall into the manhole. Can be prevented.

  Further, by forming a vertical portion that rises upward in the fixing member, the ladder body is rotated from the lying down state to the standing state, so that the insertion portion of the sliding member is attached while sliding on the inclined surface of the vertical portion. The ladder main body can be held upright by being automatically fitted into the locking groove by the biasing force of the biasing member.

  In addition, by providing a lock releasing taper portion that can be moved up and down at the insertion portion, the insertion portion of the sliding member is inserted into the engagement groove portion of the vertical portion in a tightly closed state, so that the ladder main body rattles. In addition, when the ladder body is changed from the standing state to the lying state, the insertion portion can be smoothly removed from the locking groove portion by the lock releasing taper portion.

In addition, when standing upside down, the ladder main body is placed on the upper wall of the receiving frame by keeping the ladder main body moving toward the base end by the length of the slot while resisting the biasing force of the biasing member when standing up. without pulling the ladder body proximally is manually in order to prevent the contact tip of, it becomes possible to automatically perform a series of lodging operations.

  Further, since the falling frame is provided with the ladder for preventing the fall, the worker can ascend and descend the manhole safely by raising the ladder body.

  Further, the insertion portion of the fall prevention ladder according to the present invention has one end side formed in a taper shape, and the other end side is attached with a lock releasing taper portion which is slidable in the vertical direction. The other end side of the portion is configured not to contact the inner surface of the locking groove portion.

In the above configuration, by attaching a taper portion for unlocking which can be slid in the vertical direction on one side surface of the fitting portion, the fitting portion fitted in the locking groove portion formed in the vertical portion is released. In this case, one end side of the fitting portion slides upward, and at the same time, the other end side of the fitting portion moves upward, and then the unlocking taper portion is pulled upward from the inside of the upward locking groove portion with a small force. It becomes possible.

  In the fall prevention ladder according to the present invention, an inclined surface is formed at an end of the ladder in the vertical direction where the locking groove is opened.

  In the above configuration, by forming the sloped side surface of the vertical portion as an inclined surface, the fitting portion is released from the locking groove to fall down in order to fall the standing ladder, or the lying ladder is raised. A series of operations until the fitting portion is fitted into the locking groove portion can be performed smoothly.

  Further, the fall prevention ladder according to the present invention has an elongated hole portion pivotally supported on the base end side of the ladder body so as to be rotatable and slidable against the urging force of the urging member. When standing, it moves and maintains the base end side by the length of the long hole portion, and when lying down, the ladder main body is released from the biasing force by the biasing member, and the ladder main body is moved to the long hole portion. Means for moving to the base end side by the length of.

  In the above configuration, the ladder main body is moved and maintained toward the base end by the length of the long hole when standing, so that the tip of the ladder main body does not come into contact with the upper wall of the receiving frame when lying down and is attached. Since the urging force by the urging member is released, the tip end of the ladder body and the receiving frame are automatically engaged.

  In the following, embodiments of the present invention will be described with reference to the drawings for understanding of the present invention.

Example 1
FIG. 1 is a plan view showing a fall prevention ladder according to the present invention (hereinafter simply referred to as “ladder”) and a receiving frame for a lid for an underground structure equipped with the ladder, and FIG. 2 is a support portion and an upper wall provided on the receiving frame. FIG. 3 is a plan view showing an embodiment of a ladder according to the present invention, and FIG. 4 is a cross-sectional view taken along line AA in FIG.

In FIG. 1, a lid 1 for an underground structure is composed of an annular receiving frame 2 in plan view and a lid main body (not shown) attached to the receiving frame 2 so that the lid main body is flush with the ground surface. Installed. The lid body is pulled up above the receiving frame 2 when the lid is opened, and is opened by horizontal turning or vertical inversion via a hinge mechanism. The inner peripheral surface 2a of the receiving frame 2 is formed with a mounting portion 4 having a through hole at the tip, and as shown in FIG. 2, the inner peripheral surface 2a on the side facing the mounting portion 4 is provided on the inner peripheral surface 2a. A support portion 6 having an engagement protrusion 5 on the front edge and an upper wall 7 above the support portion 6 are formed.
The ladder 8 is attached to the attachment portion 4 of the receiving frame 2 by a fixing member 9 provided on the base end side thereof, and the lid body can be fitted to the receiving frame 2 in a state where the ladder 8 is mounted.

As shown in FIGS. 3 and 4, the ladder 8 includes a pair of left and right fixing members 9, a base end shaft 10 whose left and right ends are fixed to the fixing member 9, and a base end shaft 10 that is rotatable and slidable. It is comprised from the ladder main body 11 connected so that it could move.
As shown in FIG. 5, the fixing member 9 is composed of a horizontal portion 12 and a vertical portion 13, and a groove portion 14 having an arcuate bottom surface is formed at the corner portion, and a drain hole 15 is formed in the groove portion 14. is doing.
The horizontal portion 12 is formed with an opening hole 16 for fixing the mounting portion 4 with bolts and nuts to support the base end of the ladder main body 11 raised in the groove portion 14 and prevent it from descending. .
Further, an insertion hole 18 through which the base end shaft 10 is inserted is formed in the vertical portion 13, and a recess-like locking groove portion 20 is formed at the upper end thereof. The vertical portion 13 is formed with an inclined surface 21 so that when the fixing member 9 is attached to the attachment portion 4, the front surface thereof (the ladder lying direction side) is inclined.

  The ladder body 11 includes a pair of left and right side bars 22, 22, three horizontal rails 23 connecting these side bars 22, 22 and an overhanging portion 24 projecting outward, and left and right side bars 22, 22 And a locking member 25 that is slidable along the side wall 22. In addition, on the base end side of these side rods 22, 22, an oblong slot 26 for loosely inserting the base end shaft 10 and the fixing member 9 when the ladder body 11 is raised. A stopper portion 27 that contacts the bottom surface of the groove portion 14 is formed, and a concave portion 28 that engages with the engaging protrusion 5 of the support portion 6 in a lying state is formed on the distal end side.

The lock member 25 includes a coil spring 29 as an urging member and a sliding member 30 that is constantly pressed against the fixed member 9 by the coil spring 29. As shown in FIG. 6, the sliding member 30 includes a guide portion 31 for allowing the side rod 22 to be inserted and being slidable with respect to the side rod 22, and a horizontally projecting shape with respect to the guide portion 31. A support rod receiving portion 33 that is formed and to which the support rod 36 of the coil spring 29 is connected is provided. In addition, a fitting portion 32 having a shape that can be fitted into a locking groove portion 20 formed in the vertical portion 13 of the fixing member 9 is formed on the upper portion of the guide portion 31. Further, a fitting groove portion 34 that engages with the base end shaft 10 is integrally extended at a lower portion of the guide portion 31.

  Here, the fitting portion 32 has one side end 19 formed in a taper shape, and is attached to the other end side 19A in a state where the lock releasing taper portion 35 can be moved up and down, and the lower end thereof is curved. It is formed.

As shown in FIG. 7, one end of a support rod 36 is connected to the support rod receiving portion 33 of the sliding member 30. A coil spring 29 is extrapolated to the support rod 36, and the coil spring 29 is loosely inserted in a compressed state into a support rod insertion horizontal rail 37 attached between the side rods 22 and 22, and the respective support rods are further inserted. A grip rod 37 a is attached between the other ends of 36.
In this way, the sliding member 30 is pressed against the fixed member 9 by the urging force of the coil spring 29 attached in a compressed state between the support rod receiving portion 33 and the support rod insertion horizontal crosspiece 37.

  Next, attachment of the ladder 8 will be described. As shown in FIG. 8, the fixing member 9 is disposed on the lower surface of the mounting portion 4, and is fastened and fixed by bolts and nuts 17 in a state where the through hole of the mounting portion 4 and the opening hole 16 of the fixing member 9 are aligned. Further, as shown in FIG. 9, the base shaft 10 is formed with screw portions 38 at both ends thereof and loosely inserted into the long hole portions 26 formed in the left and right side rods 22, 22 of the ladder body 11. The screw portions 38 at both ends are inserted into the insertion holes 18 in the vertical portion 13 of the fixing member 9 and fixed by the nuts 39. Therefore, the ladder body 11 is configured to be rotatable by the long hole portions 26 formed in the left and right side bars 22 and 22 and to be slidable in the front-rear direction by the length of the long hole portion 26.

  Next, how to use the ladder 8 will be described. As shown in FIGS. 9 and 10 (a), (b), and (c), when the ladder 8 is used for fall prevention, first, the standing ladder 8 is as shown in FIG. The fitting portion 32 of the sliding member 30 that is externally inserted into the side rod 22 so as to be vertically slidable is fitted into the locking groove portion 20 of the vertical portion 13 of the fixing member 9 by the biasing force of the coil spring 29.

  The ladder 8 in such a standing state is pulled up upward while holding the holding rod 37a provided between the other ends of the support rod 36 shown in FIG. The sliding member 30 to be connected slides, and the fitting portion 32 moves upward from the locking groove portion 20 as shown in FIG.

  Here, when the insertion portion 32 moves upward, one end side 19 of the insertion portion 32 slides against friction with the inner surface of the locking groove portion 20 and the other end side of the insertion portion 32. At the same time, 19A also moves upward with only the unlocking taper portion 35 engaged with the inner surface of the locking groove portion 20. Next, the lock releasing taper portion 35 attached in a state where it can be moved up and down is released from engagement with the inner surface of the locking groove portion 20 and moved upward, so that the fitting portion 32 is detached from the locking groove portion 20. It can be removed.

Next, as shown in FIG. 10 (c), the insertion portion 32 of the sliding member 30 is moved to the opening end position of the locking groove portion 20, and the insertion portion 32 is formed in a curved shape as shown in FIG. By opening the gripping rod 37a with the lower end thereof in contact with the inclined surface 21 of the locking groove portion 20, the fitting portion 32 is pressed against the inclined surface 21 of the locking groove portion 20 by the urging force of the coil spring 29. From this state, as shown in FIG. 11, the ladder body 11 is pressed toward the base end by the length of the long hole portion 26 formed in the side flange 22 while resisting the urging force of the coil spring 29. By sliding, the entire ladder body 11 moves to the fixing member 9 side, and as a result, the distal end of the side rod 22 moves to the proximal end side by the length of the long hole portion 26. Accordingly, the support frame 2 is rotated without contacting the upper wall 7, and the pressure on the ladder main body 11 is released at a position below the upper wall 7, whereby the support rod insertion horizontal rail 37 is moved by the coil spring 29. As a result of the biasing force in the direction of pushing toward the distal end side, the ladder body 11 is slid toward the distal end side by the length of the long hole portion 26 formed in the side rod 22.
Accordingly, the recess 28 formed at the tip of the side wall 22 of the ladder main body 11 is engaged with the engagement protrusion 5 formed at the support portion 6 of the receiving frame 2, and the tip of the ladder main body 11 is positioned below the upper wall 7. is doing. For this reason, it is possible to prevent the ladder main body 11 from shifting to the base end side, and the upper wall 7 prevents the ladder main body 11 from being lifted by the lifting pressure.

  Therefore, even if a lift of the manhole is generated due to a temporary increase in rainfall, and the lock of the lid body (not shown) attached to the receiving frame 2 is removed from the receiving frame 2 and opened, The ladder 8 can be maintained in a lying state, and passersby can be prevented from falling into the manhole.

  On the other hand, when the ladder main body 11 is erected from this state, the ladder main body 11 is moved by the length of the long hole portion 26 by moving the side rod 22 to the proximal end side against the urging force of the coil spring 29. It will slide to the base end side. Thereby, the engagement between the concave portion 28 of the ladder main body 11 and the engagement protrusion 5 formed on the support portion 6 of the receiving frame 2 is released, and the ladder main body 11 is raised without the tip of the ladder main body 11 coming into contact with the upper wall 7. be able to. At this time, the sliding member 30 slides the inclined surface 21 toward the opening end side of the locking groove portion 20 in a state where the fitting portion 32 is pressed against the inclined surface 21 of the locking groove portion 20 by the biasing force of the coil spring 29. become.

  Here, when the fitting portion 32 is automatically fitted into the locking groove portion 20 by the urging force of the coil spring 29, one end side 19 formed in a tapered shape of the fitting portion 32 is one end side of the locking groove portion 20. The unlocking taper portion 35 attached to the inner surface and the other end side 19 </ b> A of the fitting portion 32 so as to be movable up and down is fitted to the inner surface of the other end side of the locking groove portion 20. Accordingly, the one end side 19 of the fitting portion 32 is engaged with the inner surface of the locking groove portion 20 without a gap by the pressure release contact with the inner surface of the other end side of the locking groove portion 20 while the unlocking taper portion 35 moves upward. As a result, the ladder body 11 can be held in an upright state without any backlash.

  In this way, the operator automatically releases the sliding member by releasing the engagement between the concave portion 28 of the ladder main body 11 and the engagement protrusion 5 formed on the support portion 6 of the receiving frame 2 and raising the ladder main body 11. The insertion portion 32 of 30 is inserted into the locking groove portion 20 of the fixing member 9, and the ladder main body 11 can be held upright.

Example 2
Next, it is possible to maintain the state where the fall prevention ladder according to the present invention described in detail in the first embodiment is moved to the base end side by the length of the long hole portion while resisting the urging force by the urging member. An example in the case of adding the means will be described in detail.

FIG. 12 is a perspective view showing a state in which the ladder body is attached to the fixing member.
The ladder body 11 includes a pair of left and right side bars 22, 22, three horizontal rails 23 connecting these side bars 22, 22 and an overhanging portion 24 projecting outward, and left and right side bars 22, 22 And a locking member 25 that is slidable along the side wall 22. In addition, an elongated hole portion 26 for loosely inserting the proximal shaft 10 and a protruding mooring claw 40 are formed on the proximal end side of these scissors 22 and 22, and on the distal end side, As shown in FIG. 2, a recess 28 is formed that engages with the engagement protrusion 5 of the support portion 6 in a lying state. Further, fixing members 9 are attached to both ends of the base end shaft 10.

  Here, the fixing member 9 is composed of a horizontal portion 12 and a vertical portion 13 as shown in FIGS. 13 (a), 13 (b) and 13 (c), and the horizontal portion 12 has bolts attached to the mounting portion 4 (see FIG. 8). An opening hole 16 for fixing with a nut is formed. Further, an insertion hole 18 through which the base end shaft 10 is inserted is formed in the vertical portion 13, and a recess-like locking groove portion 20 is formed at the upper end thereof. The vertical portion 13 is formed with an inclined surface 21 so that when the fixing member 9 is attached to the attachment portion 4, the front surface (the ladder lying direction side) is inclined.

  An opening groove 41 is formed at the corner portion of the horizontal portion 12 and the vertical portion 13 so that the bottom surface can be inserted through the base end of the side rod 22. The mooring claw 40 is provided at one end of the opening groove portion 41. An engaging groove 42 having an arcuate curved surface to be anchored is formed. As shown in FIG. 13C, the engaging groove portion 42 is inserted into the base shaft 10 when the elongated hole portion 26 of the side rod 22 is inserted, and the elongated hole portion 26 is disposed when the side rod 22 is raised from the lying state. The mooring claw 40 bent and projected at the base end of the side rod 22 at approximately 90 degrees while moving to the base end side by the length of the length of the front end enters the upper end opening of the engagement groove 42 and turns to the lower end opening. Will move.

  Further, an elliptical protruding portion locking step 43 is provided at the outer opening end of the insertion hole 18 formed in the vertical portion 13 so as to be parallel to the bottom surface of the fixing member 9. It is formed. Then, as shown in FIG. 14, the protruding portion locking stepped portion 43 is fitted into a locking hole portion 44 opened on the proximal end side of the protruding portion 24. The locking hole 44 has an upper hole 45 having a diameter at which the upper part can fit the protruding part locking step part 43 and a lower part from the maximum diameter of the protruding part locking step part 43. And the lower hole 46 having a diameter slightly larger than the minimum diameter.

  Therefore, as shown by the imaginary line in FIG. 14, when the overhanging portion 24 is in a lying state, the locking hole 44 is changed from a vertical state to a horizontal state, and the overhanging portion locking step 43. And the lower hole portion 46 of the locking hole portion 44 are arranged in the same line, and the protruding portion 24 is connected to the protruding hole portion 44 with respect to the protruding portion locking step portion 43. It is possible to move from 45 to the lower hole 46.

  In the mechanism in which the ladder main body 11 is erected while maintaining the state of moving to the base end side in this way, first, in a state where the ladder main body 11 is lying down, it is shown in FIGS. 15 (a) and 16 (a) (b). As described above, the coil spring 29 as the biasing member generates a biasing force in a direction in which the supporting rod insertion crosspiece 37 is pushed toward the distal end side of the ladder main body 11, so that the length of the long hole portion 26 formed in the side rod 22 is increased. Accordingly, the ladder body 11 is slid toward the front end side, and the concave portion 28 formed on the front end side of the side wall 22 of the ladder main body 11 engages with the engagement protrusion 5 formed on the support portion 6 of the receiving frame 2. ing. In this case, the minimum diameter of the protruding portion locking step 43 and the lower hole 46 of the locking hole 44 are in the same row, and the protruding portion locking step 43 is the protruding portion. It will be in the state latched by the lower hole 46 of the 24 latching holes 44. FIG.

  When the ladder main body 11 is erected from this state, the side rod 22 is moved to the proximal end side against the urging force of the coil spring 29 as shown in FIGS. By doing so, the ladder main body 11 slides to the base end side by the length of the long hole portion 26, and the engagement protrusion 5 formed on the concave portion 28 at the distal end of the side rod 22 and the support portion 6 of the receiving frame 2. Is disengaged. In this case, the overhanging portion locking step 43 is engaged with the upper hole 45 of the locking hole 44 of the overhanging portion 24.

  Next, as shown in FIGS. 15 (c) and 18 (a) (b), when the side rod 22 is moved up to the base end side against the urging force of the coil spring 29, The anchoring claw 40 formed at the base end of the side rod 22 moves downward while sliding in the engagement groove portion 42 formed at the corner portion between the horizontal portion 12 and the vertical portion 13 of the fixing member 9. As a result, the side bar 22 rotates the ladder body 11 in the standing direction while resisting the urging force of the coil spring 29 by the anchoring claw 40 formed at the base end of the side hook 22 being anchored in the engagement groove portion 42, and at the same time. By rotating the locking hole 44 of the protruding portion 24 in the vertical direction, the lower hole 46 having a diameter slightly larger than the minimum diameter of the protruding portion locking step 43 is orthogonal to the same shape. The maximum diameter of the protruding portion locking stepped portion 43 is changed to face the ladder 22 while maintaining the state where the side rod 22 has moved to the base end side by the length of the long hole portion 26. It becomes possible to hold the main body 11 upright. In addition, the sliding member 30 that is extrapolated to the side bar 22 so as to be vertically slidable is inserted into the engaging groove portion 20 of the vertical portion 13 of the fixing member 9 by the fitting portion 32 by the biasing force of the coil spring 29. The

  Thereby, the ladder main body 11 is moved to the base end side by the length of the long hole portion 26 and is erected with no backlash. When lying down from this standing state, as will be described in detail with reference to FIG. 9 of the first embodiment, the gripping rod 37a provided between the other ends of the support rod 36 is pulled upward while resisting the biasing force of the coil spring 29. As a result, the insertion portion 32 is removed from the locking groove portion 20 and at the same time, the ladder body 11 is laid down. At this time, since the ladder main body 11 is held in the state of being moved to the base end side by the length of the long hole portion 26, the tip of the side rod 22 of the ladder main body 11 is placed on the upper wall 7 of the receiving frame 2. The coil spring can be laid down without abutting, and the minimum diameter of the protruding portion locking step 43 and the lower hole portion 46 of the locking hole 44 are in the same row. Due to the urging force of 29, the side rod 22 moves to the tip side by the length of the long hole portion 26, and the concave portion 28 at the tip of the side rod 22 and the engagement protrusion 5 formed on the support portion 6 of the receiving frame 2 are automatically set. Engage.

As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to an Example. For example, the unlocking taper portion that is attached to the other end side of the insertion portion described in the first embodiment so as to be vertically movable has a mechanism that fits the release taper portion into the other end side of the insertion portion. However, the present invention is not limited to this, and conversely, a mechanism may be used in which the release taper portion is formed in a cylindrical shape and the other end side of the fitting portion is fitted. Furthermore, a mechanism that allows the other end side of the insertion portion to be moved upward without being joined to the inner surface of the locking groove portion 20 by attaching a taper portion for release made of a flexible material to the other end side of the insertion portion. Absent.
In addition, by forming walls at both ends of the engaging protrusions of the support portion, it is possible to prevent the ladder body in a lying state from being laterally displaced.

Further, the engaging groove portion 42 formed in the fixing member 9 described in the second embodiment is not necessarily required, and the locking hole portion 44 opened to the overhang portion 24 and the overhang portion locking portion. Even with only the engagement with the stepped portion 43, the ladder main body 11 can be moved to the base end side by the length of the long hole portion 26 and can be maintained while resisting the urging force of the urging member. .
Further, the locking hole 44 does not necessarily need to open to the overhanging portion 24. For example, the locking hole portion 26 is formed in the side flange 22 with the long hole portion 26 and the upper hole portion 45 and the lower hole portion 46. By making the hole 44 into an elliptical cross section of the base shaft 10 inserted through the locking hole 44, the locking hole 44 is held against the urging force of the urging member. It can be made to move to the base end side by the length of

It is a top view which shows the receiving frame of the lid | cover for fall prevention which concerns on Example 1 of this invention, and the lid | cover for underground structures provided with this. It is a partially cutaway sectional view showing a state of a support part and an upper wall provided in the receiving frame. It is a top view which shows the ladder which concerns on Example 1 of this invention. It is AA arrow sectional drawing in FIG. It is a perspective view which shows the fixing member of the ladder which concerns on Example 1 of this invention. It is a perspective view which shows the sliding member of the locking member of the ladder which concerns on Example 1 of this invention. It is a top view which shows the state which attaches a locking member to the side fence of the ladder which concerns on Example 1 of this invention. It is a partially cutaway sectional view showing an example in which a fixing member is attached to the attachment portion of the receiving frame of the present invention. It is a perspective view which shows the state which attached the fixing member to the ladder main body of the ladder which concerns on Example 1 of this invention. It is explanatory drawing which shows the operating state of the sliding member of the locking member of the ladder which concerns on Example 1 of this invention. It is a notch sectional view which shows the fall state of the ladder which concerns on Example 1 of this invention. It is a perspective view which shows the state which attached the fixing member to the ladder main body of the ladder which concerns on Example 2 of this invention. It is explanatory drawing which shows the fixing member of the ladder which concerns on Example 2 of this invention. It is explanatory drawing which shows the fitting state of the level | step-difference part for the overhang | projection part latching of the base part of the ladder which concerns on Example 2 of this invention, and the locking hole part of an overhang | projection part. It is a perspective view which shows the standing state from the fall state of the ladder which concerns on Example 2 of this invention. It is a side view which shows the fall state of the ladder which concerns on Example 2 of this invention. It is a side view which shows the initial state from the fall of the ladder which concerns on Example 2 of this invention to standing. It is side surface explanatory drawing which shows the standing state of the ladder which concerns on Example 2 of this invention. It is explanatory drawing which shows an example of the ladder of the conventional lid | cover for underground structures.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lid for underground structures 2 Receiving frame 4 Mounting part 5 Engagement protrusion 6 Support part 7 Upper wall 8 Ladder (ladder for fall prevention)
DESCRIPTION OF SYMBOLS 9 Fixing member 10 Base end shaft 11 Ladder main body 12 Horizontal part 13 Vertical part 14 Groove part 15 Drain hole 16 Open hole 18 Insertion hole 19 One end side 19A Other end side 20 Locking groove part 21 Inclined surface 22 Side collar 23 Horizontal crosspiece 24 Tension Protruding portion 25 Lock member 26 Elongated hole portion 27 Stopper portion 28 Recessed portion 29 Coil spring (biasing member)
DESCRIPTION OF SYMBOLS 30 Sliding member 31 Guide part 32 Insertion part 33 Support hook receiving part 34 Fitting groove part 35 Locking taper part 36 Support hook 37 Supporting rod 37 Horizontal rail 37a Grasp hook 38 Screw part 39 Nut 40 Mooring claw 41 Opening groove part 42 Engaging groove 43 Overhanging portion locking step 44 Locking hole 45 Upper hole 46 Lower hole

Claims (5)

A ladder for fall prevention that is attached to the mounting portion formed on the inner periphery of the receiving frame so that it can be raised and lowered, and is supported by a support portion whose tip is opposed in a lying state,
It consists of a fixing member attached to the attachment part, and a ladder main body connected to and supported by the fixing member, and a base end side of the ladder main body is slidably inserted into the side wall of the ladder main body, A sliding member that is pressed against the fixing member by an urging member;
The fixing member has a vertical portion that rises upward, and a locking groove portion is opened in the vertical portion.
Further, the sliding member is formed with a fitting portion that can be fitted into the locking groove portion,
The fitting portion is formed such that one end side surface is tapered, and the other end side surface is attached with a taper portion for unlocking so as to be slidable in the vertical direction.
In a state where the fitting portion is fitted into the locking groove portion, the one end side surface is in a tapered shape, and the other end side surface is only the unlocking taper portion. The ladder for fall prevention characterized in that the standing state of the ladder main body can be maintained by abutting against the opposing surfaces of the locking groove portion . A ladder for fall prevention that is attached to the mounting portion formed on the inner periphery of the receiving frame so that it can be raised and lowered, and is supported by a support portion whose tip is opposed in a lying state,
It consists of a fixing member attached to the attachment part, and a ladder main body connected to and supported by the fixing member, and a base end side of the ladder main body is slidably inserted into the side wall of the ladder main body, A sliding member that is pressed against the fixing member by an urging member;
The fixing member has a vertical portion that rises upward, and a locking groove portion is opened in the vertical portion.
Further, the sliding member is formed with a fitting portion that can be fitted into the locking groove portion,
In the state where the ladder body is erected, the fitting portion is fitted into the locking groove, and the standing state of the ladder body can be maintained.
On the base end side of the ladder main body, an elongated hole portion is formed that is pivotally supported so as to be rotatable and slidable against the urging force of the urging member.
When lying down, the ladder body is moved to the distal end side by the length of the long hole portion, and in the standing state, the ladder body is moved to the proximal end side by the length of the long hole portion. A ladder for preventing fall is provided , characterized in that a means for maintaining it in a state is provided . A ladder for fall prevention that is attached to the mounting portion formed on the inner periphery of the receiving frame so that it can be raised and lowered, and is supported by a support portion whose tip is opposed in a lying state,
It consists of a fixing member attached to the attachment part, and a ladder main body connected to and supported by the fixing member, and a base end side of the ladder main body is slidably inserted into the side wall of the ladder main body, A sliding member that is pressed against the fixing member by an urging member;
The fixing member has a vertical portion that rises upward, and a locking groove portion is opened in the vertical portion.
Further, the sliding member is formed with a fitting portion that can be fitted into the locking groove portion,
The fitting portion is formed such that one end side surface is tapered, and the other end side surface is attached with a taper portion for unlocking so as to be slidable in the vertical direction.
In a state where the fitting portion is fitted into the locking groove portion, the one end side surface is in a tapered shape, and the other end side surface is only the unlocking taper portion. It is possible to maintain the standing state of the ladder body by abutting against the opposing surface of the locking groove,
On the base end side of the ladder main body, an elongated hole portion is formed that is pivotally supported so as to be rotatable and slidable against the urging force of the urging member.
When lying down, the ladder body is moved to the distal end side by the length of the long hole portion, and in the standing state, the ladder body is moved to the proximal end side by the length of the long hole portion. A ladder for preventing fall is provided , characterized in that a means for maintaining it in a state is provided . The fall prevention according to any one of claims 1, 2 and 3 , wherein an inclined surface is formed at an end of the vertical direction of the ladder main body in the vertical direction where the locking groove is opened. Ladder. An underground structure provided with a fall prevention ladder, wherein the fall prevention ladder according to claim 1, 2, 3, or 4 is attached to an attachment portion formed on an inner peripheral surface of the receiving frame. Receiving frame for object lid.

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