KR20220141043A - Platform ladder device - Google Patents

Abstract

The present invention relates to a platform ladder, which prevents the loss of balance, the slip and the reversion of a worker to guarantee the safety of the worker. The present invention can be small-sized and lightweight, thereby enabling a safe high-place work at a narrow place and a place where a light work is required. Therefore, the present invention provides safety, mobility, portability as well as work efficiency and convenience. To this end, the present invention relates to a platform ladder which is temporarily installed at a high place work space to enable a high place work of a predetermined height, and comprises: a foldable ladder body which is splayed with respect to each other around the hinge shaft of the upper portion while being unfolded to be supported with the ground surface, and has first and second ladder frames which are folded with each other around the hinge shaft while being folded; and a foldable safety handrail pole which is installed to be foldable at the main body portion of the ladder around the worker aboard a work plate, thereby preventing the falling of the worker aboard the work plate of the ladder main body.

Description

Platform ladder {PLATFORM LADDER DEVICE}

The present invention relates to a platform ladder, and more particularly, to prevent loss of balance, slip and fall of the operator to secure the safety of the operator, and at the same time to reduce the size and weight, so that it can be used in a narrow place or where light work is required. It relates to a platform ladder that enables safe high-altitude work, and through which, safety, mobility, portability, work efficiency and convenience can be simultaneously promoted.

In industrial sites such as construction, electricity, and telecommunications, and in orchard farms, various high-altitude work is performed.

In the case of working at height, it is common to permanently install a scaffolding device or a working platform at the working place. However, where the work place is narrow or where light work within a short time is required, a mobile ladder is mainly used.

The movable ladder includes a straight ladder, a telescopic ladder, an "A"-shaped step-up ladder, and the like, and is configured to be used by moving it to a place where high-place work is required, and to be folded and stored as needed.

However, such a conventional movable ladder, there is a disadvantage that the risk of the operator is very high.

In particular, there is a disadvantage in that the fall of the worker frequently occurs due to the cause of the worker's loss of balance, the slipping of the ladder, the fall of the ladder, and the like.

And, due to these shortcomings, there is a problem that there is a very high risk of large and small injuries to workers.

In order to solve the above problems, a so-called platform ladder having a stepped footrest fixedly has been developed and used.

The platform ladder is provided with a frame assembled at a certain height, and a plurality of scaffolds fixedly installed in steps to the frame, and then moved to a high-place work place, and then the operator moves up and down along the step-stepped scaffolding to work at high altitude. make it possible

However, the vertical platform ladder has the disadvantage of being bulky and heavy, and has a problem in that mobility and portability are poor due to these disadvantages.

And because of these problems, there is a drawback that the use is limited in a narrow place or a place where light work within a short time is required.

The present invention is to solve the problems of the prior art as described above, the object is to provide a platform ladder that can prevent the loss of balance and slip and fall of the operator.

Another object of the present invention, by configuring so as to prevent the loss of balance and slip and fall of the worker, to secure the safety of the worker, to provide a platform ladder that can prevent the fall accident of the worker.

Another object of the present invention, as well as securing the safety of the operator, to provide a small and lightweight platform ladder possible.

Another object of the present invention is to provide a platform ladder that enables safe high-altitude work in a narrow place or a place where light work is required, and can achieve safety, mobility, portability, work efficiency and convenience at the same time is to do

In order to achieve the above object, the platform ladder of the present invention is supported on the ground while being spread with respect to each other about the hinge axis of the upper part when unfolded, in the platform ladder erected at the high place work place, so that work at a specific height is possible. and a foldable ladder body having first and second ladder frames that are folded to each other about the hinge axis when folded; In order to prevent the fall of the worker riding on the working scaffold of the ladder body, it is characterized in that it comprises a foldable safety handrail that is installed to be foldable in the ladder body part of the perimeter of the worker riding the working scaffold.

And the foldable safety handrail, to spread around the perimeter of the operator's body on the working scaffold or to be folded into the ladder body, the upper and lower intervals in any one of the first and second ladder frames of the ladder body an upper balustrade rod and a lower balustrade rod which are respectively installed to be foldable; It is characterized in that it includes a connecting rod connecting the upper and lower handrails to each other so that the upper and lower handrails can be folded to the ladder body while interlocking movement.

And it further includes folding guide rods on both sides for guiding the folding of the upper and lower handrails with respect to the ladder body; The folding guide rod, one end is rotatably installed at both end portions of the upper balustrade rod, the other end is rotatably and slidably installed on the ladder body, when the folding movement of the upper balustrade rod, the upper balustrade rod It is characterized in that it rotates and guides the unfolding and folding of the upper and lower balustrade with respect to the ladder body to a certain track while rotating and sliding with respect to the ladder body.

and a stopper portion capable of fixing the foldable guide rods that have the upper and lower handrails extended with respect to the ladder body so as to maintain the unfolded state of the upper and lower handrails with respect to the ladder body; The stopper portion may include a stopper hole formed in the foldable guide rod; It is characterized in that it comprises a stopper pin installed on the ladder body so that the foldable guide rod is fitted into the stopper hole of the foldable guide rod and coupled when the upper and lower handrail rods are spread with respect to the ladder body.

In addition, the stopper pin is elastically pressed in a direction to be coupled to the stopper hole of the foldable guide bar by a spring, and when aligned with the stopper hole of the foldable guide bar in the unfolding process of the upper and lower handrail bars, the stopper hole is automatically inserted into the stopper hole. It is characterized in that it is inserted and coupled.

And the upper and lower balustrade, the first and second ladder frame of the ladder body has an opening portion that is open to any one of the frame side; The opening part is characterized in that, when moving to the uppermost working scaffold through the step-type lifting scaffolds of the corresponding frame, the worker's movement to the working scaffold is not obstructed.

And the upper and lower balustrade, characterized in that it further comprises an auxiliary balustrade that can block the opening of the upper balustrade.

According to the platform ladder according to the present invention, since it is a structure having a foldable safety handrail on the upper part of the working scaffold, there is an effect that can protect the operator on the working scaffold.

In particular, when a worker riding on a work platform loses balance, by configuring so that the worker can rely on the safety handrail, it is possible to secure the safety of the worker and prevent the worker from falling due to the loss of balance.

In addition, since it is a structure having outriggers that can support the lower part of the ladder body on the ground, it is possible to prevent the ladder from slipping and falling, and through this, it is possible to prevent the operator from falling due to the sliding and falling of the ladder. there is an effect

In addition, by providing the safety handrail and the outriggers and being foldable with a lightweight material, it is possible to secure the safety of the operator as well as to reduce the size and weight.

In addition, since it is possible to reduce the size and weight while securing the safety of the workers, it is possible to work at a safe height in a narrow place or where light work is required. At the same time, there is an effect that can be achieved.

1 is a perspective view showing the configuration of a platform ladder according to the present invention;
2 to 4 are side views showing the folding process of the platform ladder according to the present invention,
Figure 5 is a perspective view showing the unfolded state of the ladder body constituting the platform ladder of the present invention,
6 is a perspective view showing a folding safety handrail constituting the platform ladder of the present invention unfolded from the ladder body;
7 is a cross-sectional view showing a stopper for fixing the folding safety handrail constituting the platform ladder of the present invention;
8 is a cross-sectional view showing an outrigger constituting the platform ladder of the present invention;
9 is a perspective view showing another operation example of the outriggers constituting the platform ladder of the present invention.

Hereinafter, a preferred embodiment of the platform ladder according to the present invention will be described in detail based on the accompanying drawings.

First, referring to Figure 1, the platform ladder of the present invention is provided with a ladder body (10).

The ladder body 10 is made of a lightweight material, for example, an aluminum material, and has a first ladder frame 20 and a second ladder frame 30 facing each other and corresponding to each other.

The first and second ladder frames (20, 30) are each composed of a plurality of lifting boards (24, 34) connecting both supports (22, 32) and both supports (22, 32). , are connected to each other to be foldable with respect to the hinge shaft 12 of the upper part.

In particular, as shown in FIG. 2 , by being folded around the hinge shaft 12 of the upper portion, transportation and storage are facilitated.

In addition, as shown in FIG. 3, by being spread out about the hinge shaft 12 of the upper part, a "∧"-shaped structure is formed, and the first and second ladder frames 20 and 30 spread out in this way are, It is possible to be stably supported on the ground (E) of the work place.

Here, the first and second ladder frames 20 and 30 spread out in the "∧"-shaped structure are fixed to the unfolded posture by the fixing part 14 .

The fixing part 14 is composed of a working platform 15 that connects the upper portions of the first and second ladder frames 20 and 30 to each other.

The working scaffold 15 is used as a scaffold for work at height work, and is installed to be foldable in any one of the first and second ladder frames 20 and 30 .

This working scaffold 15, when folding the first and second ladder frames (20, 30), as shown in Figure 2, is configured to be folded in the frame (30).

And when the first and second ladder frames (20, 30) are unfolded in a "∧"-shaped structure, as shown in FIG. 3, while unfolding from the corresponding frame 30, the other frames 20 ) is configured to be supported by being caught on the support rod 20a.

In particular, it is configured to be supported by being caught by the support rod 20a of the other frame 20 facing the distal end of the frame 30 while extending from the top to the bottom.

Accordingly, the first and second ladder frames 20 and 30 spread out in a "∧"-shaped structure are fixed. As a result, the first and second ladder frames 20 and 30 can be constantly maintained in an unfolded posture in a "∧"-shaped structure.

Again, referring to FIG. 1 , the platform ladder of the present invention further includes a moving wheel 16 installed on the ladder body 10 .

The moving wheel 16 is installed on both sides of the lower end of any one of the first and second ladder frames 20 and 30 to enable rolling motion with the ground.

These moving wheels 16, as shown in FIG. 2, allows the first and second ladder frames 20 and 30 to be easily moved to another place in a folded state about the hinge shaft 12.

And on the frame 30 of the upper portion of the moving wheel 16, a folding auxiliary moving wheel 17 is further installed.

The folding auxiliary moving wheel 17 is installed to be foldable on the frame 30, and as shown in FIG. When transported to another place in a folded state, it is configured to be able to roll with the ground (E) while unfolding from the corresponding frame (30).

Therefore, with the moving wheels 16 on the lower side, it facilitates the movement and transport of the platform ladder of the present invention.

Again, referring to Figure 1, the platform ladder of the present invention is provided with a folding safety handrail 40 that is installed on the upper portion of the working scaffold 15 of the ladder body 10.

The foldable safety handrail 40 is an upper handrail rod ( 42) and a lower balustrade rod 44.

The upper and lower handrail rods 42 and 44 have a "??"-shaped structure having an opening portion 42a, 44a on one side, and both portions thereof are on both supports 22 of the first ladder frame 20. Each is rotatably installed.

These upper and lower balustrade rods 42 and 44 are installed to be foldable in the upper portion of the working platform 15 of the ladder body 10 .

In particular, as shown in Figures 2 and 5, by folding on the upper portion of the first ladder frame 20, when transporting the ladder body 10 to another place in a folded state, the ladder body 10 of Facilitate the transport operation.

In addition, as shown in FIGS. 4 and 6, when unfolded from the first ladder frame 20, it is arranged around the body of the operator riding on the working platform 15 of the ladder body 10. Therefore, it prevents the fall and fall of the operator riding on the working scaffold 15 of the ladder body 10 .

Here, the upper and lower handrail bars (42, 44) are installed in the first ladder frame (20), one side opening (42a, 44a) of the first ladder frame (20) of the step-type lifting platform (24) should be installed facing them.

This is to prevent the worker from interfering with the movement of the worker to the working scaffold 15 when the worker moves to the uppermost working scaffold 15 through the stepped lifting boards 24 of the first ladder frame 20 . to be.

Referring again to FIG. 1 , the foldable safety handrail 40 includes a connecting rod 46 connecting the upper handrail rod 42 and the lower handrail rod 44 in an interlocking motion.

One end of the connecting rod 46 is rotatably connected to the upper balustrade rod 42 , and the other end is rotatably connected to the lower balustrade rod 44 .

This connecting rod 46 allows the upper balustrade rod 42 and the lower balustrade rod 44 to interlock.

In particular, as shown in Figures 3 and 4 and 5, in order to fold the upper and lower balustrade rods 42, 44 to the ladder body 10, any one of the upper and lower balustrade rods 42, 44 When rotating to the side of the first ladder frame 20, the other one is also rotated interlockingly at the same time.

Accordingly, the upper and lower balustrade rods 42 and 44 can be folded into the ladder body 10 while simultaneously interlocking.

Conversely, in order to spread the upper and lower handrail rods 42 and 44 from the ladder body 10, when rotating any one of the upper and lower handrail rods 42 and 44 from the first ladder frame 20, the other One of them rotates interlockingly at the same time.

Accordingly, the upper and lower balustrade rods 42 and 44 can be unfolded from the ladder body 10 while simultaneously interlocking.

Again, referring to FIG. 1 , the foldable safety handrail 40 includes the folding guide rods 48 on both sides for guiding the folding of the upper and lower handrail bars 42 and 44 with respect to the first ladder frame 20 . include more

One end of the folding guide rod 48 is rotatably installed on both end portions of the upper handrail rod 42 , and the other end is rotatably and slidably installed on the first ladder frame 20 .

This folding guide rod 48, when the upper and lower balustrade rods 42 and 44 are unfolded or folded from the first ladder frame 20, rotates with respect to the upper balustrade rod 42, and the first ladder The frame 20 guides the unfolding and folding of the upper and lower handrails 42 and 44 with respect to the first ladder frame 20 while rotating and sliding.

In particular, when the upper and lower balustrades 42 and 44 are unfolded from the first ladder frame 20, by guiding the unfolding of the upper and lower balustrades 42, 44 with respect to the first ladder frame 20, The upper and lower balustrade rods (42, 44) enable the first ladder frame (20) to be spread horizontally while having a constant trajectory.

And the foldable safety handrail 40 has a stopper part 49 that can fix the foldable guide bar 48 that is horizontally spread out with the upper and lower handrail bars 42 and 44 with respect to the first ladder frame 20. be prepared

As shown in FIGS. 1 and 7 , the stopper part 49 includes a stopper hole 49a formed in the foldable guide bar 48 and the foldable guide bar 48 is rotated to the first ladder frame 20 . and a support member 49b that slidably supports, and a stopper pin 49c installed on the support member 49b so as to be fitted and coupled to the stopper hole 49a of the folding guide rod 48 .

The stopper pin 49c is, when the foldable guide bar 48 spreads the upper and lower handrail bars 42 and 44 horizontally with respect to the first ladder frame 20, the foldable guide bar 48 of the It is configured to be fitted while being aligned with the stopper hole 49a.

Accordingly, the folded guide rod 48 of the upper and lower balustrade rods 42 and 44 is fixed. Accordingly, the upper and lower handrails (42, 44) to maintain a horizontally unfolded posture with respect to the first ladder frame (20).

Here, as shown in FIG. 7 , the stopper pin 49c is configured to be elastically pressed in a direction coupled to the stopper hole 49a of the folding guide rod 48 by a spring 49d.

This is to enable the stopper pin 49c to be automatically inserted into the stopper hole 49a and coupled thereto in the process of unfolding the upper and lower handrails 42 and 44 .

On the other hand, when you want to fold the upper and lower handrail rods 42 and 44 on the ladder body 10, pull the pull handle 49e installed on the stopper pin 49c, and then pull the stopper pin from the stopper hole 49a. (49c) is taken out and detached.

Referring again to FIG. 1 , the foldable safety handrail 40 further includes an auxiliary handrail 50 capable of blocking the one side openings 42a and 44a of the upper handrail 42 .

The auxiliary balustrade 50 has a "??"-shaped structure, and both portions thereof are rotatably installed on both sides of the upper balustrade rod 42 , respectively.

This auxiliary balustrade rod 50 is installed to be foldable up and down on the upper balustrade rod 42 so as to block one side open portion 42a of the upper balustrade rod 42 .

In particular, as shown in Figs. 4 and 6, when the operator boards the working scaffold 15 of the ladder body 10, it is folded toward the openings 42a and 44a of the upper handrail 42. Block the openings (42a, 44a) of the upper balustrade (42).

Therefore, the fall and fall of the operator through the opening (42a, 44a) side of the upper balustrade 42 is prevented.

In addition, when the operator steps on the step-type lifting platform 24 of the first ladder frame 20 in order to board the uppermost working platform 15, it spreads upward and the upper handrail 42 of the The openings 42a and 44a are opened. Thus, it allows the movement of the operator to the work platform (15).

Again, referring to Figure 1, the platform ladder of the present invention, the lower portion of the ladder body 10 is further provided with an auxiliary support 60 for auxiliary support to the ground (E).

The auxiliary support unit 60 includes a plurality of outriggers (62) respectively installed on both lower sides of the first and second ladder frames (20, 30).

The outriggers 62 are, as shown in FIG. 8, the outrigger legs 64 that are foldably installed on both supports 22 and 32 of the first and second ladder frames 20 and 30, respectively. include

The outrigger leg 64 is folded on both supports 22 and 32 of the first and second ladder frames 20 and 30 when the ladder body 10 is transported or stored, respectively.

And, when the ladder body 10 is installed while being spread out in a "∧"-shaped structure in the work place, the first and second ladder frames 20 and 30 are spread from both supports 22 and 32 of the ground (E). ) is supported.

Accordingly, the lower portion of the first and second ladder frames (20, 30) is supported on the ground (E). Thus, the ladder body 10 of the present invention can be stably supported on the ground (E).

Meanwhile, the outriggers 62 further include a locking part 66 for locking the outrigger legs 64 supported on the ground E.

As shown in FIG. 8, the locking part 66 is rotatably installed on the ladder body 10 part above the outrigger leg 64, and the distal part 66a-1 is the outrigger leg ( 64) and the locking bar 66a to fix the end portion 66a-1 of the locking bar 66a to the upper surface portion of the outrigger leg 64. It includes a stopper (66b) installed on the.

The locking bar 66a is rotatably installed on the ladder body 10 to have the same folding direction as the outrigger leg 64, and the distal end portion 66a-1 of the outrigger leg 64 is It is configured to correspond to the upper surface part. In particular, it is configured to be received in a locking groove 64a formed along the longitudinal upper surface of the outrigger leg 64 .

Here, since the locking bar 66a has the same folding direction as the outrigger leg 64, it is folded to the ladder body 10 together with the outrigger leg 64.

The stopper 66b is movably installed on the distal end portion 66a-1 of the locking bar 66a, and the stopper 66b thus installed has the bottom surface of the locking groove 64a of the outrigger leg 64 and The distal end portion 66a-1 of the locking bar 66a is fixed to the outrigger leg 64 while in frictional contact.

In particular, the stopper 66b is elastically pressed in the direction of frictional contact with the bottom surface of the locking groove 64a of the outrigger leg 64 by the return spring 66c.

The stopper 66b elastically pressurized in this way, when the outrigger leg 64 is supported on the ground E while unfolding from the ladder body 10, the bottom surface of the locking groove 64a of the outrigger leg 64 in frictional contact with

Accordingly, the distal end portion 66a-1 of the locking bar 66a is fixed to the outrigger leg 64 . As a result, the locking bar 66a can support the upper surface of the outrigger leg 64 , and as a result, the outrigger leg 64 can be locked while being supported on the ground E.

Here, the locking bar 66a and the stopper 66b are configured to make frictional contact with the bottom surface of the locking groove 64a while moving along the locking groove 64a of the outrigger leg 64 .

Accordingly, the outrigger leg 64 can be locked regardless of the unfolding angle of the outrigger leg 64 .

In particular, as shown in FIG. 9 , it is supported on the ground E-1 that protrudes compared to the other ground E parts, and it is also possible to lock the small outrigger legs 64 having different unfolding angles.

Accordingly, it is possible to lock all the outrigger legs 64 of the ladder body 10 irrespective of the unfolding angle.

As a result, the outriggers 62 are spread out in accordance with the topographical structure of the ground (E), it is possible to efficiently support the lower portion of the ladder body (10) on the ground (E).

On the other hand, when you want to release the locked outrigger leg 64, as shown in FIG. 1, by pulling the release handle 66a-2 installed on the locking bar 66a, the outrigger leg 64 What is necessary is to release the stopper 66b in frictional contact with the bottom surface of the locking groove 64a.

According to the platform ladder of the present invention having such a configuration, since it is a structure having a foldable safety handrail 40 on the upper portion of the working scaffold 15 , it is possible to protect the worker riding on the working scaffold 15 .

In particular, when a worker riding on the work platform 15 loses balance, by configuring so that the worker can rely on the safety handrail 40, the safety of the worker can be secured and the worker from falling due to the loss of balance can be prevented. .

In addition, since it is a structure having outriggers 62 that can support the lower part of the ladder body 10 on the ground (E), it is possible to prevent slip and fall of the ladder, and through this, the sliding and fall of the ladder It can prevent accidents caused by falling workers.

In addition, by providing the safety handrail 40 and the outriggers 62 and being foldable with a lightweight material, it is possible to secure the safety of the worker as well as to reduce the size and weight.

In addition, since it is possible to reduce the size and weight while securing the safety of the workers, it is possible to work at a safe height in a narrow place or where light work is required. can be done at the same time.

In the above, preferred embodiments of the present invention have been exemplarily described, but the scope of the present invention is not limited to such specific embodiments, and can be appropriately changed within the scope described in the claims.

10: ladder body 12: hinge axis
14: fixed part 16: work platform
16: transfer wheel 17: folding auxiliary transfer wheel
20: first ladder frame (Frame) 20a: support bar
22: support 24: lifting platform
30: second ladder frame 32: support
34: lifting platform 40: folding safety handrail
42; upper balustrade 42a: opening
44: lower balustrade 44a: opening
46: connecting rod 48: folding guide rod
49: stopper portion 49a: stopper hole (Stopper Hole)
49b: support member 49c: stopper pin (Stopper Pin)
49d: Spring 49e: Pull handle
50: auxiliary balustrade 60: auxiliary support
62: Outrigger 64: Outrigger Leg
64a: locking groove 66: locking part
66a: locking bar 66a-1: distal end
66a-2: release knob 66b: stopper
66c: Return Spring E: Ground

Claims (17)

In the platform ladder to be erected in the high-place work place to enable high-altitude work of a specific height,
The first and second ladder frames 20 that are supported on the ground E while being spread apart from each other about the hinge shaft 12 of the upper part when unfolded, and are folded with each other about the hinge shaft 12 when folded. , 30) with a foldable ladder body 10 and;
In order to prevent the fall of the worker riding on the working scaffold 15 of the ladder body 10, a folding type that is installed to be foldable in the ladder body 10 of the perimeter of the worker riding the working scaffold 15 Platform ladder comprising a safety handrail (40). The method of claim 1,
The foldable safety handrail 40,
Any one of the first and second ladder frames (20, 30) of the ladder body (10) so as to be spread around the perimeter of the operator's body riding on the working scaffold (15) or to be folded on the ladder body (10) an upper balustrade rod 42 and a lower balustrade rod 44 which are respectively installed to be foldable at an upper and lower interval in one;
Including a connecting rod 46 connecting the upper and lower balustrade rods 42 and 44 to each other so that the upper and lower balustrade rods 42 and 44 can be folded to the ladder body 10 while interlocking movement Features a platform ladder. 3. The method of claim 2,
It further includes folding guide rods 48 on both sides for guiding the folding of the upper and lower handrail rods 42 and 44 with respect to the ladder body 10;
The folding guide rod 48,
One end is rotatably installed on both end portions of the upper handrail bar 42, and the other end is rotatably and slidably installed on the ladder body 10,
During the folding motion of the upper balustrade 42, the upper balustrade for the upper balustrade 42 rotates, and rotates and slides with respect to the ladder body 10, while the upper and Platform ladder, characterized in that it guides the unfolding and folding of the lower balustrade (42, 44) to a constant track. 4. The method of claim 3,
The upper and lower handrails 42 and 44 are spread with respect to the ladder body 10 so as to maintain the expanded state of the upper and lower handrails 42 and 44 with respect to the ladder body 10. a stopper portion 49 capable of fixing the folding guide rod 48;
The stopper portion 49,
a stopper hole (49a) formed in the folding guide rod (48);
When the folding guide rod 48 spreads the upper and lower handrail rods 42 and 44 with respect to the ladder body 10, the folding guide rod 48 is inserted into the stopper hole 49a of the ladder body 10 and can be coupled. Platform ladder, characterized in that it comprises a stopper pin (49c) installed on the ladder body (10) so that. 5. The method of claim 4,
The stopper pin 49c is,
It is elastically pressed in a direction coupled to the stopper hole 49a of the folding guide rod 48 by a spring 49d,
When aligned with the stopper hole 49a of the folding guide rod 48 during the unfolding process of the upper and lower handrail rods 42, 44, it is automatically inserted into and coupled to the stopper hole 49a. platform ladder. 6. The method of claim 5,
The upper and lower handrail rods 42 and 44 are,
and an opening portion (42a, 44a) that is opened to the side of any one of the first and second ladder frames (20, 30) of the ladder body (10);
The openings (42a, 44a) are,
Platform ladder, characterized in that when moving to the uppermost working scaffold 15 through the step-type lifting boards 22 of the frame 20, the worker's movement to the working scaffold 15 is not obstructed. . 7. The method of claim 6,
The upper and lower handrail rods 42 and 44 are,
Platform ladder, characterized in that it further comprises an auxiliary balustrade rod (50) that can block the opening (42a, 44a) of the upper balustrade rod (42). 8. The method of claim 7,
The auxiliary balustrade 50 is,
Both parts are rotatably installed on both sides of the opening parts 42a and 44a of the upper handrail 42, respectively,
When the operator boards to the side of the working scaffold 15, the opening portions 42a and 44a of the upper handrail 42 are rotated upward to allow the opening of the opening portions 42a and 44a,
After the operator boarding on the side of the working scaffold 15, the platform ladder, characterized in that the opening (42a, 44a) is blocked while being folded toward the opening (42a, 44a) of the upper handrail (42). 9. The method of claim 8,
Platform ladder, characterized in that it further comprises an auxiliary support (60) for supporting the lower portion of the ladder body (10) auxiliary to the ground (E). 10. The method of claim 9,
The auxiliary support 60,
The platform ladder, characterized in that it comprises a plurality of outriggers (Outrigger) (62) respectively installed on both the lower sides of the first and second ladder frames (20, 30) of the ladder body (10). 11. The method of claim 10,
The outriggers 62 are
The first and second ladder frames (20, 30) are installed to be foldable, respectively, when transporting or storing the ladder body (10), the first and second ladder frames (20, 30) Each is folded, and when the ladder body 10 is installed in the work place, the outrigger legs 64 supported on the ground (E) while unfolding from the first and second ladder frames (20, 30) and;
Platform ladder, characterized in that it further comprises a locking portion (66) for locking the outrigger leg (64) supported on the ground (E). 12. The method of claim 11,
The locking part 66,
In a state where the ladder body 10 is rotatably installed on the upper side of the outrigger leg 64, the distal end portion 66a-1 has a locking bar 66a corresponding to the upper surface of the outrigger leg 64 and ;
A stopper 66b that locks the rotation of the outrigger leg 64 supported on the ground E by fixing the distal end portion 66a-1 of the locking bar 66a to the upper surface portion of the outrigger leg 64 ) platform ladder comprising a. 13. The method of claim 12,
The stopper 66b,
It is movably installed in the distal end portion (66a-1) of the locking bar (66a),
The return spring (66c) is elastically pressed in the direction of frictional contact with the bottom surface of the locking groove (64a) formed along the upper surface of the outrigger leg (64) in the longitudinal direction,
When the outrigger leg 64 is extended from the ladder body 10 and supported on the ground E, the locking bar ( Platform ladder, characterized in that the distal portion (66a-1) of 66a) is fixed to the outrigger leg (64). 14. The method of claim 13,
To separate the stopper 66b in frictional contact with the bottom surface of the locking groove 64a of the outrigger leg 64 from the bottom surface of the locking groove 64a, Platform ladder, characterized in that it further comprises a release handle (66a-2) to be installed. 15. The method of claim 14,
The locking bar (66a) is,
It is rotatably installed on the ladder body 10 so as to have the same folding direction as the outrigger leg 64, and is simultaneously folded on the ladder body 10 together with the outrigger leg 64 platform ladder. 16. The method according to any one of claims 1 to 15,
The ladder body 10 is,
Platform ladder, characterized in that it is provided with moving wheels (16) to facilitate transport by rolling motion with the ground during transport. 17. The method of claim 16,
It further includes a folding auxiliary moving wheel (17) that is installed to be foldable on the ladder body (10),
The folding auxiliary moving wheel 17 is a platform, characterized in that when the ladder main body 10 is transported, it is unfolded from the ladder main body 10 and performs rolling motion with the ground (E) together with the moving wheel 16 ladder.

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