JP4722891B2 - Ceiling work ladder - Google Patents

Description

  The present invention relates to a ceiling work ladder.

Conventionally, a ladder that works on the ceiling (high place) has two ladder halves with left and right struts erected on the left and right pillars, and pivots in a face-to-face manner so that it can be fixed in a square shape or a straight line. What is worn (ladder ladder) is known. (For example, refer to Patent Document 1). In addition, there is known a structure (sliding ladder) in which a short ladder-like leg portion is overlapped in parallel and slidably connected so that the length can be adjusted.
Registered Utility Model No. 3063945

  When working on the ceiling by pulling out (longening) the stored leg body with a slide ladder, or when working on the ceiling with two ladder halves deployed in a straight line with a stepladder, wall surfaces, etc. It was necessary to use it leaning on.

  However, when the ladder is leaned against the wall surface, the work can be performed only at the ceiling (high place) near the wall surface, and the operator's hand cannot reach at a position away from the wall surface, so the work cannot be performed easily. Therefore, when exchanging a fluorescent lamp or the like (light bulb or guide display member), although it is difficult to carry, a large stepladder fixed in a U-shape has been used. In addition, although cost and time are required, scaffolds and the like have been installed with temporary members (iron pipes, clamps, etc.).

  Especially for work on emergency stair landings in buildings (where the floor area is narrow and the work target member is installed at the ceiling position away from the wall), the conventional ladder is sufficient in height, but the work target Workers sometimes did not reach the members (fluorescent lamps, indicators, etc.). In addition, a large stepladder ladder could not secure a sufficient width of a leg for stable installation. For this reason, although it is inefficient, it takes time and cost to temporarily assemble a scaffold on a narrow floor surface.

  The problem to be solved is that when the ladder is stood against the wall surface, the work can be performed only on the wall side.

  Therefore, an object of the present invention is to provide a ceiling work ladder capable of easily and quickly performing a ceiling work at a position away from the wall.

In order to achieve the above object, a ladder for a ceiling work according to the present invention includes a first ladder half that is pivotally connected to each other in a linearly deployed ladder state and an inverted V-shaped stepladder state. In the ceiling work ladder having the first ladder half and the second ladder half, a connecting pivot joint for pivoting the first ladder half and the second ladder half so that the first ladder half and the second ladder half can be folded in two is provided at an intermediate position in the longitudinal direction. the as Jo possibility accommodated folded at one end of the first ladder half and second ladder halves became expanded ladder state of contact with the expanded ladder state in the vertical wall becomes horizontal development shape while being pivotally mounted A wall surface abutting support member for supporting the first ladder half and the second ladder half, and the wall surface abutting support member is configured to horizontally support a plurality of reinforcing members between a pair of square pipe-shaped support members. Reinforcement that is a reinforcing member that is formed in the shape of a U-shaped ladder and disposed in the narrow portion of the C-shaped The timber, on the top end踏桟which is踏桟to be laid in the vicinity of the end portion, is attached via a pivot bracket hinge type, the wall abutting the support member, housed housed folds In the state, the pair of square pipe-shaped support members are provided with a contact portion projecting toward the end portion side of the endmost reinforcing member, and the wall surface contact support member is in a horizontally deployed state in which the wall surface contact support member contacts the vertical wall surface. A swing restricting mechanism for restricting the wall surface contact support member from swinging further upward from the horizontally deployed state, with a lower surface of the contact portion coming into contact with a horizontal contact surface of the endmost crosspiece. Further, when the abutting portion comes into contact with the abutting surface, a lock member disposed so as to sandwich the pair of abutting portions is attached to the abutting surface, and the lock can be protruded face-to-face from the locking member. Insert the flange into the lock hole formed on the outer surface of the contact part, and The support member is obtained a holding locking mechanism in the horizontal deployed condition.

Also, in which the wall surface contact support member, and telescopic fixed.

  According to the high work ladder according to the present invention, since the wall contact support member is provided, the high work can be performed at a position away from the wall. Further, since the first and second ladder halves are folded and housed on the pivoted side, the wall surface abutting member does not get in the way (is not bulky) and can be easily carried.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
FIG. 1 is an explanatory view for explaining a use state of a ceiling work ladder according to the present invention, and FIGS. 2 to 5 show a first embodiment of the present invention. In the first embodiment, after the U-shaped receiving members 12 and 12 are fixed to a pair of left and right square pipe-shaped support columns 11 and 11, respectively, the U-shaped opening is face-to-face. in the post 11, 11 arranged, having a first ladder half 1 was ladder shape bridged so as to sandwich the踏桟10 made several aluminum fixed as. Further, similarly to the first ladder half 1, the second ladder half 2 is formed in a ladder shape by installing a step rail 10 on a pair of left and right columns 11, 11 to which receiving members 12, 12 are fixed. Yes.

  Further, the first ladder half 1 is arranged so that the end surfaces of the left and right columns 11 of the first ladder half 1 and the end surfaces of the left and right columns 11 of the second ladder half 2 face each other so as to form one linear ladder. In the longitudinal direction, the left and right struts 11 and 11 of the first ladder half 1 and the left and right struts 11 and 11 of the second ladder half 2 are connected to the connecting pivot attachment plates 13 and 13 made of thin metal plates. The joint pivot part 7 is provided pivotally. The first ladder half 1 and the second ladder half 2 can be bent around the connection pivot axis P of the connection pivots 13 and 13 of the connection pivot 7. Further, by swinging around the connecting pivot axis P, a linear deployed ladder state (see FIGS. 1 to 3), an inverted V-shaped stepladder state (see FIG. 4), and a short ladder state (see FIG. 4). And (see FIG. 5). Further, in the inverted V-shaped stepladder state, resin anti-slip members 14, 14, 14, 14 are attached to the outermost ends of the columns 11, 11, 11, 11 that contact the floor surface C ( (See FIG. 4).

  Then, the first ladder half 1 and the second ladder half 2 that are in the shape of a straight ladder (in an expanded ladder state) are in contact with and supported by the vertical wall surface A in a horizontally expanded state in use. A contact support member 3 is provided (see FIG. 1). The wall surface abutting support member 3 includes a pair of metal U-shaped support members 31, 31 arranged in a cross-sectional view so that the U-shaped opening portions face each other, and a plurality of metal polygonal pipes The support members 31 and 31 are formed into a U-shaped ladder shape in a plan view by fixing both ends of the reinforcing member 30 so as to be fitted in a U shape. Further, an anti-slip member 14 made of resin is attached to the outermost ends of the support members 31 that come into contact with the vertical wall surface A.

  The wall surface abutting support member 3 is pivotally attached to one end 8 of the connected first ladder half 1 and second ladder half 2. In other words, the first ladder half 1 is pivotally attached to the end of the first ladder half 1 that is opposite to the connecting pivot part 7. FIG. 6 shows an enlarged view of the main part of the one end 8. 7 is a cross-sectional view taken along the line AA, FIG. 8 is an explanatory view taken along the line BB, and FIG. 9 is a view when the wall surface abutting support member 3 is in a horizontally developed state. FIG.

  The pivoting structure of the wall surface contact support member 3 and the first ladder half 1 is a pivoting bracket (hinge bracket) in which two swing plates 50a, 50a swingable around the bracket axis L are pivotally mounted. One swing plate 50a of 50 is attached to the most end tread 10a which is the step 10 of the first ladder half 1 in the vicinity of one end 8, and the other swing plate 50a is attached to the wall surface. In this structure, the abutting support member 3 is attached to an outermost reinforcing member 30a which is the outermost reinforcing member 30. That is, the metal fitting axis L of the pivot fitting 50 becomes the pivot pivot axis L between the wall surface abutting support member 3 and the first ladder half 1, and pivots around the pivot pivot axis L. The wall surface abutting support member 3 is pivotally attached to the first ladder half 1 as possible.

  Further, in the above-described linear deployment ladder state (see FIG. 2) or inverted V-shaped stepladder state (see FIG. 4), the side on which the user moves up and down is the front (lifting surface) side. The contact support member 3 is pivotally attached to the back surface (non-lifting surface) side so that it can be folded back. In the above-described short ladder state (see FIG. 5), the first ladder half 1 is folded and then sandwiched by the second ladder half 2 so as to be sandwiched.

Further, the wall surface abutting support member 3 is in the folded storage state, and the support member 31 forms a contact portion 31a that protrudes toward the one end portion 8 from the outermost reinforcing member 30a (see FIG. 8). ). When the wall contact member 3 is swung in the deployment direction R ₁ (in the direction of arrow R ₁ shown in FIG. 8), the contact portion 31a of the wall contact support member 3 is Is set so as to suppress the swing at a predetermined obtuse angle θ (90 ° to 130 °) (see FIG. 9). In other words, the surface on the one end portion 8 side of the most end tread bar 10a is used as a contact surface 21, and the contact portion 31a of the support member 31 is brought into contact with the rocker when swinging, and further upward (deployment direction R) during use. It is provided with a swing regulating mechanism 20 for restraining the swinging to _1).

  By this swing regulating mechanism 20, the angle swung between the storage state of the wall surface contact support member 3 and the horizontal deployed state when the wall surface contact support member 3 is used in contact with the vertical wall surface A is used. Becomes a predetermined obtuse angle θ. That is, the wall surface abutting support member 3 can swing in the section of the predetermined obtuse angle θ (90 ° to 130 °).

  In addition, a lock member 40 (Nanjing drop-shaped bracket or round drop-shaped bracket) on which the lock rod 42 protrudes and stores by reciprocating operation of the operation rod 41 is attached to the end 8 side surface (contacting surface 21) of the end stepping rail 10a. ing. The lock member 40 is configured such that the lock rod 42 can be held in a protruding state or a stored state by locking the operation rod 41 in a locking groove formed in the casing of the lock member 40. Further, the lock member 40 is arranged so that the protruding direction of the lock rod 42 is opposed so that the left and right contact portions 31a and 31a are sandwiched when the contact portion 31a contacts the contact surface 21. Yes. Further, the contact portion 31a forms a lock hole 43 through which the lock rod 42 can pass when being brought into contact with the contact surface 21.

  That is, when the abutting portion 31a is brought into contact with the abutting surface 21, the lock member 40 is operated so that the lock rod 42 penetrates the lock hole 43 formed in the abutting portion 31a, and the lock rod 42 is held in a protruding state. Thus, the lock mechanism 4 is provided that can hold the wall surface abutting support member 3 in a horizontally developed state.

  In addition, a folding hook plate-like width stopper 46 that can fix the open leg width of the inverted V-shaped stepladder is provided in the vicinity of the connecting pivot portion 7 of the second ladder half body 2, and the first ladder In the vicinity of the connecting pivot part 7 of the half body 1, a width stop pin 45 capable of locking the width stop metal 46 is attached.

  Although not shown, a storage locking hole is formed in the vicinity of the end of the wall surface contact support member 3 on the contact side with the vertical wall surface A, and is inserted into the storage locking hole on the back side of the ladder half 1. It is desirable to provide a storage holding mechanism capable of holding the wall surface abutting support member 3 in a stored state by attaching a storage locking member that can be locked.

  Further, on the other end 9 of the first ladder half 1 and the second ladder half 2 (the end of the second ladder half 2 which is the end opposite to the one end 8), the floor surface A hook member 26 for preventing misalignment that can be locked to the sucker member F and the anchor member attached to the rear is pivoted by a metal hinge member 27 so that the hook member 26 can be stored so as to be folded on the back surface (non-lifting surface) side. It is desirable to attach and attach (refer to FIG. 2). Further, it is desirable to provide a hook holding member 28 (in the form of a Nanjing drop fitting) that holds the folded state.

Next, the second embodiment will be described in detail.
The first ladder half 1 and the second ladder half 2 formed in the same manner as in the first embodiment described above are pivotally attached in the same configuration. That is, it is pivotally connected to a linear deployment ladder state, an inverted V-shaped stepladder state, and a short ladder state. Expansion and contraction fixing that supports the first ladder half 1 and the second ladder half 2 in a deployed ladder state (in a linear ladder state) in contact with the vertical wall surface A in a horizontally deployed state in use. A flexible wall surface abutting support member 3 is provided. The wall surface abutting support member 3 that can be fixed and expanded is pivotally attached to one end portion 8 in the same manner as in the first embodiment, can be folded and stored on the pivoted side, and can be stored horizontally. In the unfolded state, a rocking restriction mechanism 20 similar to that of the first embodiment for restricting the wall surface abutting support member 3 from rocking upward (in the unfolding direction) is provided, and can be swung with a predetermined obtuse angle θ. I have to.

  The wall surface abutting support member 3 includes a pair of metal square pipe-shaped support members 31 and 31 arranged in parallel, and is fixed so that a plurality of metal polygonal pipe-shaped reinforcing members 30 are installed. It is a shape. Further, the support member 31 has a metal prismatic auxiliary support member 34 provided therein. The auxiliary support member 34 is housed in the support member 31 so as to be protruded and housed. The auxiliary support member 34 has a plurality of through-holes 36 formed in the vertical direction in the use state (the wall surface contact support member 3 is in a horizontally deployed state). Further, the support member 31 has a positioning hole 37 that is formed so as to penetrate in the vertical direction in a use state (the wall surface contact support member 3 is in a horizontally deployed state). Further, the wall surface abutting support member 3 that can be freely expanded and contracted includes a positioning pin 33 that fixes the adjustment hole 36 and the positioning hole 37 in a skewered shape (see FIG. 10). Further, a resin non-slip member 14 is attached to the outermost end of the auxiliary support member 34 on the side in contact with the vertical wall surface A.

  In other words, the wall surface contact support member 3 that can be stretched and fixed according to the second embodiment is a stretchable member that can be freely adjusted in length by pulling out (projecting) the auxiliary support member 34 from the support member 31. is there. Further, the wall surface abutting support member 3 can be fixed at a predetermined length by making the positioning hole 37 and the adjustment hole 36 concentric and the positioning pin 33 in a skewered shape.

  Further, the lock mechanism 4 that can hold the horizontally developed state is provided in the square pipe-shaped support member 31 by forming a lock hole 43 into which a lock rod 42 similar to that of the first embodiment can be inserted. Similarly to the first embodiment, the width stop metal fitting 46, the width stop pin 45, the storage holding member for holding the storage state of the wall surface abutting support member 3, and the hook member 26 for preventing displacement. It is desirable to attach a hook holding member 28.

  In the present invention, the design can be changed. For example, the wall surface abutting support member 3 is pivoted to the end of the second ladder half 2 (the other end 9 opposite to the one end 8). You may wear it. That is, it is pivotally attached to either one of the first ladder half and the second ladder half 2.

  In addition to the above, the lock mechanism 4 uses the lock rod 42 that is elastically biased so that the lock rod 42 is always protruded by the elastic member, and the contact portion 31a abuts against the contact surface 21. At this time, the lock rod 42 may be inserted into the lock hole 43 along the contact portion 31a to hold the wall surface abutting support member 3 (notch type).

  Further, the wall surface abutting support member 3 may be a concept that can be fixed in a stretchable manner other than those described in the second embodiment. FIG. 11 shows another example of the wall surface abutting support member 3. For example, a ratchet groove 38 is formed in the auxiliary support member 34, and a swingable ratchet locking member 39 that is always elastically biased by the elastic member and locked so as to be inserted into the ratchet groove is provided in the support member 31. It is also possible to make it extendable and fixable by using a ratchet mechanism. FIG. 12 shows another example of the wall surface abutting support member 3. An adjustment hole 36 is formed in the square pipe-shaped auxiliary support member 34, a positioning hole 37 is formed in the support member 31, and a positioning pin 33 that is constantly energized and urged by the elastic member is attached. The wall contact support member 3 can be fixed to be stretchable and fixed by inserting the positioning pins 33 into the positioning holes 37 and the adjusting holes 36 and fixing them.

A method (action) of using the above-described ceiling work ladder according to the present invention will be described.
A fluorescent lamp b is installed on the ceiling B (high place) at a position away from the vertical wall surface A at the landing site of the emergency staircase in the building, and the fluorescent lamp b is located in a place where the floor C serving as a scaffold is narrow (see FIG. 1). First, the first and second ladder halves 1 and 2 are placed in a linear deployment ladder state, and the wall surface abutting support member 3 is deployed. At this time, the abutting portion 31a of the wall surface abutting support member 3 abuts against the abutting surface 21 of the outermost tread bar 10a and is controlled to swing at a predetermined obtuse angle θ (for example, 105 °) (see FIG. 9).

  Moreover, the lock hole 43 formed in the contact part 31a becomes concentric with the lock rod 42 of the lock member 40 attached to the contact surface 21 of the endmost tread bar 10a. Then, the operation rod 41 is operated so as to hold the lock rod 42 in a protruding state. Then, the lock rod 42 is smoothly passed through the lock hole 43, and the wall surface contact support member 3 is fixed at a predetermined obtuse angle (deployment angle) θ.

  With the first and second ladder halves 1 and 2 in the unfolded ladder state and the wall surface abutting support member 3 in the unfolded state, the wall surface abutting support member 3 abuts on the vertical wall surface A of the landing of the staircase. Stand up. The wall surface abutting support member 3 is horizontal and abuts against the vertical wall surface A to support the first and second ladder halves 1 and 2 in the deployed ladder state. That is, the first and second ladder halves 1 and 2 in the deployed ladder state are in a state of leaning apart from the vertical wall surface A by the length of the substantially wall surface contact support member 3. That is, a position farther from the vertical wall surface A of the ceiling B can be operated than the operation position D on the conventional ladder shown by the one-dot chain line in FIG.

  Further, the wall surface abutting support member 3 and the first and second ladder halves 1 and 2 in the deployed ladder state are deployed at a predetermined obtuse angle θ (for example, 105 °), and the wall surface abutting support member 3 is horizontal. Therefore, the first and second ladder halves 1 and 2 in the deployed ladder state are inclined with respect to the floor C at a predetermined inclination angle α (for example, 75 °) that is optimal for raising and lowering and work. (See FIG. 1).

  In addition, when the hook member 26 is attached, the hook member 26 at the other end 9 of the first and second ladder halves 1 and 2 is unfolded and engaged with the suction cup member F attached to the floor C. Stop.

  Therefore, in the ceiling work ladder according to the present invention, the fluorescent lamp b can be easily replaced at a position away from the vertical wall surface A of the ceiling B. The operator raises and lowers the first and second ladder halves 1 and 2 in the deployed ladder state, and replaces the fluorescent lamp b.

  When working other than the ceiling B away from the vertical wall surface A, the lock member 40 of the wall surface contact support member 3 is operated to release the lock, and the wall surface contact support member 3 is swung. Then, it becomes a linear long ladder shape that is housed on the opposite side of the lifting surface and that can work near the vertical wall surface A. In other words, the work near the wall becomes possible. When the first and second ladder halves 1 and 2 are swung around the connecting pivot axis P, and the width stopper 46 is locked to the width stopper pin 45, an inverted V-shape that can be used as a stepladder. (See FIG. 4). Further, when the width stopper 46 is removed and the first and second ladder halves 1 and 2 swing around the connecting pivot axis P, the straight short ladder is easy to carry and clean up. It becomes a shape (see FIG. 5).

  Further, as in the second embodiment described above, when the wall surface abutting support member 3 is made to be extendable and fixable, the auxiliary support member is positioned so that the operator can work in an easy posture for work. 34 is protruded or housed, the expansion / contraction adjustment hole 36 is concentrically aligned with the positioning hole 37, and the positioning pin 33 is inserted in a skewered manner. That is, the wall surface abutting support member 3 is adjusted to a desired length according to the work object (for example, the fluorescent lamp b or the guidance display object) on the ceiling B at a position away from the vertical wall surface A.

  As described above, according to the present invention, the first ladder half 1 and the second ladder half 2 that are pivotably attached to each other in a linearly deployed ladder state and an inverted V-shaped stepladder state are switchable. And a wall contact support member 3 for supporting the first ladder half 1 and the second ladder half 2 in the deployed ladder state in contact with the vertical wall surface A in a horizontally deployed state. The wall surface abutting support member 3 is pivotally attached to one end 8 of either the first ladder half 1 or the second ladder half 2, and the first ladder half 1 and the second ladder half 2 Since it is folded and stored on the above-mentioned pivotally mounted side, the work target member (fluorescent lamp b, guide indicator, etc.) on the ceiling (high place) away from the vertical wall surface A Work easily and quickly. Further, there is no need to assemble a temporary scaffold or the like, and the operation can be easily and inexpensively. Even if it is a place where a large stepladder is difficult to open (a place where the floor surface C is narrow), it can be easily installed. Further, since it can be switched between a straight deployment ladder state, an inverted V-shaped stepladder state, and a straight short ladder state, it can be used for various operations. Further, since the wall surface abutting support member 3 is folded and stored on a surface (back surface) opposite to the lifting surface, the wall surface abutting support member 3 is not hindered when the wall surface abutting support member 3 is not used (stored state). You can In addition, it can be easily folded and folded.

  In addition, a swing restriction mechanism 20 is provided for restricting the wall surface contact support member 3 from swinging further upward in the horizontally deployed state, and the wall surface contact support member 3 is folded and stored. Further, since it is configured to be swingable at a predetermined obtuse angle θ between the horizontal deployment state, the wall surface abutting support member 3 does not swing upward (deployment direction), so that the work can be performed more safely. . In addition, it is possible to easily and quickly be in a horizontally deployed state at a predetermined obtuse angle θ that is an optimal installation state for work. In addition, the linear deployment ladder state can be easily and quickly set to the optimum predetermined tilt angle α. The deployed ladder state of the first and second ladder halves 1 and 2 can be leaned against the vertical wall surface A while maintaining a predetermined inclination (tilt) angle α, and work can be performed safely.

  In addition, since the wall surface abutting support member 3 is extendable and fixable, the work can be easily performed according to (adjusting) the position of the work target member at a high place on the ceiling or the like away from the vertical wall surface A. Further, it is not necessary for the operator to work in an unreasonable posture (a state such as a back stretch, a forward turn, a shrimp warp posture, etc.), and the work can be performed safely and easily. Further, the wall surface abutting support member 3 can be stored more compactly. Moreover, it can be easily carried.

It is explanatory drawing explaining the use condition of the ladder for ceiling work which concerns on this invention. 1st Embodiment is a side view of a deployment ladder state. 1st Embodiment is a rear view of a deployment ladder state. 1st Embodiment is a side view of a stepladder state. 1st Embodiment is a side view of a short ladder state. It is a principal part enlarged view. It is AA sectional drawing of FIG. FIG. 8 is a cross-sectional explanatory view taken along the line BB in FIG. 7 in which the wall surface abutting support member is stored. It is principal part expanded sectional explanatory drawing of a wall surface contact | abutting support member in a horizontal expansion | deployment state. It is a principal part expanded sectional view of the wall surface contact support member 3 of 2nd Embodiment. It is a principal part expanded sectional view which shows another example of the wall surface contact | abutting support member 3. FIG. It is a principal part expanded sectional view which shows another example of the wall surface contact | abutting support member 3. FIG.

1 First Ladder Half 2 Second Ladder Half 3 Wall Contact Support Member
4 Locking mechanism
7 Connecting pivot 8 One end
10 pedestrian
10a Endmost pier
20 Swing regulation mechanism
21 Contact surface
30 Reinforcing member
30a Endmost reinforcing member
31 Support member
31a per part
40 Lock member
42 lock
43 Lock hole
50 Pivoting bracket A Wall surface θ Predetermined obtuse angle

Claims (2)

Ceiling work having a first ladder half (1) and a second ladder half (2), which are pivotally connected to each other in a linearly deployed ladder state and an inverted V-shaped stepladder state. In the ladder for
A connecting pivot part (7) for pivotally pivoting the first ladder half (1) and the second ladder half (2) in a foldable manner in the middle in the longitudinal direction;
Becomes horizontal development shape while being pivoted as can be accommodated folds at one end (8) of the first ladder half became expanded ladder state of the linear (1) and the second ladder half (2) A wall surface contact support member (3) that contacts the vertical wall surface (A) and supports the first ladder half (1) and the second ladder half (2) in the deployed ladder state ;
The wall surface abutting support member (3) is formed in a C-shaped ladder shape in which a plurality of reinforcing members (30) are horizontally mounted between a pair of square pipe-shaped support members (31) (31). An endmost reinforcing member (30a), which is a reinforcing member (30) disposed in a narrow portion of the character, is connected to an endmost stepping rail (10a) that is a stepping rail (10) installed in the vicinity of the end portion (8). ) Is attached via a hinged pivot bracket (50)
The wall surface abutting support member (3) is folded and stored , and the pair of square pipe-shaped support members (31) and (31) are connected to the end part (30a) more than the end reinforcing member (30a). 8) Provided with contact portions (31a) and (31a) projecting to the side,
In the horizontally developed state where the wall surface abutting support member (3) is in contact with the vertical wall surface (A), the lower surface of the contact portion (31a) (31a) is the horizontal surface of the end tread (10a) A rocking regulation mechanism (20) that is in contact with (21) and regulates the wall surface abutting support member (3) from further rocking upward from the horizontally deployed state;
Furthermore, when the said contact part (31a) (31a) contact | abuts to the said contact surface (21), the locking member (40) (40) arrange | positioned so that a pair of contact part (31a) (31a) may be pinched | interposed ) Is attached to the contact surface (21), and lock rods (42) and (42) that can protrude in a face-to-face manner from the lock members (40) and (40) are connected to the outer surfaces of the contact portions (31a) and (31a). For ceiling work, comprising a lock mechanism (4) that can be inserted into the lock holes (43) and (43) formed on the wall and can hold the wall surface abutting support member (3) in the horizontally deployed state . ladder. The ceiling work ladder according to claim 1 , wherein the wall surface contact support member (3) is extendable and fixable .

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