JP2021123939A - Insulation footstool - Google Patents

Abstract

To provide an insulation footstool satisfying all of the properties of insulation, load bearing, and weight saving.SOLUTION: An insulation footstool in an embodiment of this invention comprises: a top plate portion whose outer peripheral face is formed of an acryl-modified resin and in which a metal aggregate is disposed in an inner space closed by the outer peripheral face; a pair of ladder-like leg portions formed of a fiber-reinforced plastic and supporting the top plate portion; and a hinge mechanism formed of a metal or a resin whose surface is applied with an insulation coating and connecting the leg portion to the top plate portion so as to be folded.SELECTED DRAWING: Figure 1

Description

The present invention relates to a stepping stone having an insulating property (insulated stepping stone).

For example, when performing work such as electrical work, workers often use stepladders and stepladders. However, conventional stepladders and stepladders have an insulating resin cover, an insulating sheet, or the like attached to the surface of an aluminum stepladder or stepladder, and it cannot be said that the insulating property is sufficient due to its structure. .. Furthermore, when the legs are folded and carried, the aluminum portion may be exposed and the insulating property may be impaired. For this reason, conventional stepladders and stepladders have been worried about electric shock and ground faults in the energized part near the work.

It is also being considered to form the entire stepladder with fiber reinforced plastic (FRP) instead of aluminum. However, if the whole is made of fiber reinforced plastic, the amount of glass fiber used increases in order to secure the load capacity, and the total mass increases as compared with the one made of aluminum, which increases the burden on the operator such as carrying. In particular, this problem becomes remarkable when the FRP is manufactured by drawing out.

That is, although the use of resin as the material can be expected to improve the insulating property, the trade-off between the load capacity of the product and the total mass becomes a problem as compared with the product made of aluminum. In particular, a stepladder having a larger top plate area than a stepladder has a safety problem unless not only the legs but also the top plate does not have a predetermined load capacity. However, if it is formed of FRP like the legs, the total mass becomes so large that it becomes difficult to carry. Therefore, it has been difficult to make the step ladder all-resin in the past.

Draft Registration No. 3102055 Draft Registration No. 3136052 JP-A-2018-178390

The present invention has been made based on such circumstances, and an object of the present invention is to provide an insulating step that satisfies all the characteristics of insulation, load capacity, and weight reduction.

The insulating step of the present invention is formed of a top plate portion in which an outer peripheral surface is formed of an acrylic modified resin and a metal aggregate is arranged in an internal space sealed by the outer peripheral surface, and a fiber reinforced plastic. It is provided with a set of ladder-shaped legs that support the portions, and a hinge mechanism that is formed of metal or resin having an insulating coating on the surface and connects the legs to the top plate portion so as to be foldable. It is characterized by that.

It is a perspective view of the insulation platform which concerns on embodiment of this invention. It is a top view of the said insulation step. It is a side view in the longitudinal direction of the said insulation step. It is a side view in the lateral direction of the said insulation step. It is an internal block diagram of the top plate part of the said insulation step. It is a perspective view of the hinge mechanism (with a lock mechanism) of the said insulation step. It is a perspective view of the hinge mechanism (without a lock mechanism) of the said insulation step.

Hereinafter, an insulating step according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the technical scope of the present invention is not limitedly interpreted by the embodiments described below.

As shown in FIGS. 1 to 4, the insulating step 1 according to the present embodiment has, for example, a top plate portion 2 on which an operator is placed to perform work, and a set of leg portions 3 that support the top plate portion 2 from below. The main configuration is a hinge mechanism 4 that connects each leg portion 3 independently and foldably to the top plate portion 2.

The top plate portion 2 is formed in, for example, a rectangular thick plate shape. The flat shape of the upper surface of the top plate is, for example, a rectangle that is easy for workers to work on. As a preferable example, the upper surface of the top plate portion 2 is subjected to fine embossing (not shown) to prevent slipping, and a step 21 to prevent slipping is provided on the outer peripheral edge over the entire circumference. Of course, the planar shape of the top plate portion 2 is an example, and it is not excluded to make any other shape such as a square, a polygon, a circle, an ellipse, or a curved shape. The outer peripheral surface covering the entire top plate portion 2 (six surfaces in this example) is formed of an acrylic modified resin. The acrylic-modified resin is a resin having impact resistance, and acrylic-modified polyvinyl chloride is used as a preferable example. Specifically, for example, the trade name: Kaidak (registered trademark) is used. The thickness of the outer peripheral surface (that is, the acrylic modified resin) is set within the range of, for example, 1 mm to 3 mm.

The configuration of the top plate portion 2 will be described in more detail with reference to the internal configuration diagram of FIG. The outer peripheral surface of the top plate portion 2 is formed by mutually combining parts including an upper surface plate 22, a back surface plate 23, a pair of side plates 24 in the longitudinal direction, and a pair of side plates 25 in the lateral direction. One of the side plates 24 and 25 is omitted for convenience of drawing. Each of the side plates 24 and 25 has a U-shaped vertical cross section, and the laminated top plate 22, the square pipe 5 and the back plate 23 described later are engaged with the U-shaped portion. The U-shaped upper side portions of the side plates 24 and 25 form a non-slip step 21. On the contrary, the outer peripheral corners of the side plates 24 and 25 are chamfered in an R shape as an example.

Each part 22 to 25 on the outer peripheral surface is, for example, a molded product of an acrylic modified resin. In the case of the insulated step 1 in which the worker exclusively rides and works by himself / herself, as an example, the sizes of the upper surface plate 22 and the back surface plate 23 are 598 mm in length, 348 mm in width, and 2 mm in thickness. The size of the pair of side plates 24 in the longitudinal direction is 580 mm in length, 45 mm in height, and 1 mm in thickness. The size of the pair of side plates 25 in the lateral direction is 350 mm in length, 45 mm in height, and 1 mm in thickness.

When the material of the top plate portion 2 is made of resin, the insulating property is improved, but the load capacity is lowered. Therefore, in the present embodiment, the metal aggregate is arranged inside the top plate portion 2 in which the sealed space is formed of the acrylic modified resin to ensure the insulating property. The metal aggregate is, for example, a metal pipe. A square pipe 5 made of aluminum is preferable. As an example, when the top plate portion 2 is designed to have a length of 600 mm, a width of 350 mm, and a height of 45 mm, for example, nine square pipes 5 having an outer side of 38 mm square and a length of 595 mm are arranged in parallel. The thickness of the square pipe 5 is, for example, 0.7 mm. In this case, the direction in which the square pipes 5 are arranged is the lateral direction of the top plate portion 2. In other words, all the square pipes 5 are arranged so as to straddle the pair of leg portions 3. The adjacent square pipes 5 are fixed by fixing means. The fixing means is not particularly limited, and in addition to adhesives and welding, fixing tools such as screws can be used.

In a configuration in which a plurality of square pipes 5 are arranged in parallel, in order to withstand bending stress when a large load is applied to the center, in the present embodiment, inside the square pipes 5 at both ends, as a preferable example, in the length direction of the pipes. A reinforcing material for wood 6 is provided along the above. As a preferable example, a plate-shaped wood having the same length as the square pipe 5 (first wood 61), a plate-shaped wood shorter than the first wood 61 (second wood 62), and a second wood 62 A shorter plate-shaped wood (third wood 63) is laminated in the lateral direction toward the center side of the top plate portion 2, and this is inserted into the square pipe 5 and fitted. The length of the second wood 62 is, for example, 120 mm, and the length of the third wood 63 is, for example, 110 mm. Adjacent wood 61-63 are fixed to each other with, for example, an adhesive.

The thickness of each of the wood 61 to 63 is set to, for example, a thickness obtained by dividing the length of the inner side of the square pipe 5 into three (preferably equally divided). For example, when the inner side of the square pipe 5 is 36 mm square, the thickness of each wood 61 to 63 is 12 mm. Further, the vertical width of each of the timbers 61 to 63 is aligned with the length of the inner side of the square pipe 5. As a result, the three laminated first to third timbers 61 to 63 are fitted so as to fill both ends of the square pipe 5 without gaps.

Further, plate-shaped wood (fourth wood 64) is fitted into the openings at both ends of the remaining seven square pipes 5 excluding the square pipes 5 at both ends as a reinforcing material. The fourth wood 64 has, for example, a similar shape that fills the opening of the square pipe 5 without gaps. For example, when the inner side of the square pipe 5 is 36 mm square, a square timber having a length and width of 36 mm square and a thickness of 10 mm is used. The fourth wood 64 may be individually fitted to the square pipe 5, or as shown in FIG. 5, the fourth wood 64 may be previously attached to the side plate 25 in the lateral direction and collectively fitted to the square pipe 5. You may.

In this way, by arranging the square pipes 5 in parallel as the metal aggregate and applying the wood 6 as the reinforcing material, the target load capacity is secured while suppressing the increase in the total mass of the top plate portion 2. There is. Moreover, since the reinforcing material is composed of the first timber 61 which is the same length as the square pipe 5 and the second to fourth timbers 62 to 64 arranged only on both ends of the square pipe 5, the minimum necessary timber is used. Is being reinforced efficiently. The length of the third wood 63 located on the center side of the second wood 62 is set shorter to withstand the bending stress in the horizontal direction, and a large load is applied to the center of the top plate portion 2. It contributes to withstanding the bending stress at the time. The wood 6 as a reinforcing material may be configured to include at least the first wood 61. Furthermore, an alternative material equivalent to that of wood 6 may be used.

Further, metal plates 65 are arranged at both ends of the first wood 61 by cutting out a part on the outer surface side. The metal plate 65 is, for example, an iron plate having a length of 100 mm, a width in the vertical direction of 36 mm, and a thickness of 3 mm. Taps (so-called threaded holes 66) are formed from the outside on the side plates 24, the square pipes 5, and the metal plates 65 of the acrylic modified resin laminated in order from the outside. The threaded hole 66 is used to fix a screw as a fixture for attaching the hinge mechanism 4 to the top plate portion 2. The threaded holes 66 are M6 taps as an example, and are formed at 6 locations on one side (3 locations on each end).

Subsequently, the leg portion 3 will be described. As shown in FIGS. 1 to 4, the insulating step 1 is arranged so that a pair of ladder-shaped legs 3 face each other on both sides of the top plate 2 in the lateral direction. Each leg 3 is independently foldable by a pair of left and right hinge mechanisms 4. A preferred example is a pair of two legs 3, but it does not necessarily have to be two legs. That is, it does not exclude the arrangement of the leg portions 3 forming a set with, for example, three or more legs according to the shape of the top plate portion 2.

The main body of the leg portion 3 is formed in a ladder shape in which the front view (side view of the insulating step 1 in the lateral direction) is substantially trapezoidal. For example, when the height of the insulating step 2 is set to 600 mm, one footrest 31 extending in the lateral direction is provided in the middle of the leg 3 main body. However, even if it does not have the lateral footrest 31, it is included in the shape of a ladder. A non-slip sheet 31a is attached to the surface of the hanging footrest 31. The footrest 31 is preferably formed integrally with the main body of the leg portion 3. The leg 3 main body is formed of fiber reinforced plastics (FRP). As a preferable example, the drawing process is not adopted, and the molding is performed by hand lay-up using a mold.

Specifically, a mold corresponding to the main body of the leg 3 is prepared, and a gel coating agent is applied to the surface of the mold as a release agent. Subsequently, for example, a glass fiber mat material is laid on the surface of the mold, and a matrix resin is applied and attached. This work is repeated, for example, to a thickness of 3 mm to 5 mm, preferably 4 mm, and after drying, it is removed from the mold to form a leg 3. Therefore, as shown in FIG. 1, the leg portion 3 has a chevron-shaped (for example, substantially trapezoidal) horizontal cross section. The ratio of the glass fiber to the matrix resin is preferably set to glass fiber = 40 to 45% by mass: matrix resin = 55 to 60% by mass.

In the case of the drawing process, since the directions of the glass fibers are aligned in one direction, the ratio of the glass fibers is generally 60% by mass or more, which is not suitable for realizing weight reduction. In order to keep the ratio of glass fibers within the range of 40 to 45% by mass, hand layup is adopted in this embodiment. The synergistic effect of the configuration of the top plate portion 2 described above, the configuration of the leg portion 3, and the configuration of the hinge mechanism 4 described later results in high load capacity (1000N as an example) and weight reduction (total as an example). It has achieved a mass of 8.5 kg). It is preferable to use wax as the release agent to form the legs 3 having a glossy outer peripheral surface. Further, it is preferable to improve the design of the entire insulating step 1 by using a matrix resin such as white.

At the tip of the leg portion 3, a leg cap (covering material) 32 having an insulating property and having elasticity so as not to damage the floor surface is provided. For the leg cap 32, for example, a molded product of vinyl chloride is used. In order to prevent the leg cap 32 from falling off, the leg cap 32 and the leg 3 main body are fixed with a fixture (not shown) such as a bolt. Since it is made entirely of resin, it is preferable to use resin bolts or the like as the fixture. Alternatively, it may be a metal fixture having an insulating coating on the surface.

Subsequently, the hinge mechanism 4 will be described. As shown in FIG. 2, the hinge mechanism 4 for connecting the top plate portion 2 and the leg portion 3 is arranged in pairs on both side surfaces of the top plate portion 2 and the leg portion 3. Among them, the lock mechanism 7 of each leg portion 3 is added to the hinge mechanism 4 (41) arranged diagonally of the top plate portion 2. A hinge mechanism 4 (42) having no locking mechanism 7 is arranged on the other diagonal line. The lock mechanism 7 locks (fixes) the leg portion 3 in a state in which the leg portion 3 is opened and in a state in which the leg portion 3 is folded.

FIG. 6 is a perspective view of the hinge mechanism 4 (41) having the lock mechanism 7, and FIG. 7 is a perspective view of the hinge mechanism 4 (42) having no lock mechanism 7. As shown in FIGS. 6 and 7, the hinge mechanisms 4 (41, 42) arranged on both sides of one leg 3 are symmetrically configured (excluding the lock mechanism). Therefore, the hinge mechanism 4 (41, 42) can share the portion excluding the lock mechanism 7.

The hinge mechanism 4 (41, 42) rotates the first hinge blade 43 fixed to the top plate 2, the second hinge blade 44 fixed to the leg 3, and the hinge blades 43, 44 to each other. It is provided with a connecting portion 45 that is movably connected. The connecting portion 45 is composed of, for example, a screw and a nut, and rotatably connects the hinge blade portions 43, 44 to each other through the opening holes formed in the hinge blade portions 43, 44. A plurality of opening holes 43a are formed on the surface of the first hinge vane portion 43, and the screw 43b (see FIG. 1) as a fixture is inserted into the screw hole 66 (FIG. 1) of the top plate portion 2 through the opening holes 43a. 5). As a result, the first hinge blade portion 43 is fixed to the top plate portion 2. Similarly, a plurality of opening holes 44a are formed on the surface of the second hinge wing portion 44, and a screw 44b (see FIG. 1) as a fixture is formed on the side surface of the leg portion 3 through these opening holes 44a. Screw it into the screw hole (not shown). As a result, the second hinge vane 44 is fixed to the leg 3.

Support pieces 43c and 44c formed by bending inward, for example, are formed on the first hinge vane 43 and the second hinge vane 44, respectively. The support pieces 43c and 44c come into surface contact with each other when the legs 3 are opened (that is, the insulating step 1 is used) and receive the load from the top plate 2. As described above, in the insulating step 1 of the present embodiment, the support pieces 43c and 44c provided in the hinge mechanism 4 receive the load from the top plate portion 2, and the leg portions 3 are opened as shown in FIG. A predetermined gap C is formed between the top plate portion 2 and the upper side of the leg portion 3. This gap C functions as a buffer space C when a large load (for example, a target value of 1000 N) is applied to the top plate portion 2 and the entire insulating step 1 is distorted.

The first hinge wing 43 and the second hinge wing 44 are made of metal, and the surfaces thereof are coated with an insulating coating to ensure insulation. The metal is, for example, a hot-rolled steel material. The insulating coating is, for example, a nylon coating having a thickness of 0.3 mm. Similarly, for the connecting portion 45, screws, nuts, washers, etc. having an insulating coating on the surface are used. The connecting portion 45 may cover the exposed surface with a resin cap instead of the nylon coating. Even if it is configured in this way, it shall be included in the insulating coating. Alternatively, resin screws or nuts may be used. All or part of the first hinge vane 43, the second hinge vane 44, and the connecting portion 45 may be made of resin, but as described above, the support pieces 43c and 44c are configured to receive the load. Therefore, it is desirable that at least the first hinge vane 43 and the second hinge vane 44 are made of metal having an insulating coating on the surface.

Subsequently, the lock mechanism 7 will be described. As shown in FIG. 6, the hinge mechanism 4 (41) having the lock mechanism 7 additionally includes a columnar lock pin 71 having a finger hook bar 71a as an operation unit and an elastic member 72 such as a spring. There is. The lock pin 71 is slidably fitted into the opening hole of the pin holding portion 43d formed in the first hinge vane portion 43, and is directed outward (in the locking direction) by an elastic member 72 such as a spring. Is being urged. On the other hand, on the surface of the second hinge vane 44, the first locking hole 44d, which is locked by engaging the tip of the lock pin 71 when the leg 3 is opened, and the leg 3 are folded. In this state, the tip of the lock pin 71 is engaged to form a second locking hole 44e that is locked.

That is, when the leg portion 3 is opened with the connecting portion 45 of the hinge mechanism 4 as the rotation axis and the lock pin 71 is located at the first locking hole 44d, the locking pin 71 is subjected to the urging force of the elastic member 72. The tip enters the first locking hole 44d and is automatically locked. An operation by a worker is required to release this locked state. Specifically, a hand is inserted below the top plate portion 2, and the lock pin 71 is slid and moved in a direction opposite to the urging direction of the elastic member 72 by using the finger hook bar 71a, and for example, the other side. Hold the footrest 31 of the leg 3 with your hand and fold the leg 3. When the leg portion 3 is folded and the lock pin 71 is located at the second locking hole 44e, the tip of the lock pin 71 enters the second locking hole 44e by the urging force of the elastic member 72 and automatically enters the second locking hole 44e. Is locked.

By arranging the lock pin 71 that also serves as the operation portion in the lower region of the top plate portion 2 in this way, there are few portions protruding outward, and the operation can be performed safely. Further, the work can be safely performed by locking the legs 3 in the open state, and the carrying can be safely performed by locking the legs 3 in the folded state.

Here, when the legs 3 are locked in the folded state, it is inconvenient if the legs are not locked if the legs are provided symmetrically in the folding order. Therefore, in the present embodiment, the second locking hole 44e has a curved elongated hole shape. More specifically, a long hole for two lock pins is formed on a concentric circle centered on the rotation axis of the connecting portion 45 of the hinge mechanism 4 to form a curved long hole shape. As a result, the lock pin 71 is locked at a position closer to the tip of the elongated hole when folded first, and locked at a position closer to the rear end of the elongated hole when folded later. That is, both legs 3 can be locked regardless of which one is folded first, without the operator worrying about the order of folding. Of course, if the same lock can be realized, it does not have to be a curved elongated hole shape.

The insulated step 1 having the above-described configuration can be used as a step for electrical work, for example. Of course, not only the top plate portion 2 may be used for work, but also the top plate portion 2 may be used as a table. Further, it may be used as a storage stand on which articles such as devices are placed, or it may be used as a support leg on which two sets of insulating step 1s are arranged and a long article is placed. That is, the insulating step 1 of the present embodiment, which has three features of insulation, load capacity, and weight reduction, can be used in multiple modes in an environment requiring insulation. That is, the insulated step 1 can be said to be a multi-functional stand.

According to the above-described embodiment, an acrylic modified resin is used as the material for ensuring the insulation of the top plate portion 2, FRP is used as the material for ensuring the insulation of the leg portion 3, and the insulation of the hinge mechanism 4 is maintained. By adopting an insulating coating as a configuration for securing, it is possible to realize an all-resin insulating step 1.

By arranging the square pipes 5 arranged in parallel and the wood 6 (particularly 61) as a reinforcing material in the sealed region covered with the acrylic modified resin, the top plate portion 2 has a high load capacity. Moreover, weight reduction can be realized. Further, by setting the ratio of the glass fiber to the matrix resin to FRP in which the glass fiber = 40 to 45% by mass: the matrix resin = 55 to 60% by mass, the leg portion 3 also has a high load capacity. Moreover, weight reduction can be realized. Furthermore, by using a metal with an insulating coating, the hinge mechanism 4 can also have a high load capacity and can be reduced in weight. And by these synergistic effects, the target high load capacity (1000N as an example) and weight reduction (total mass 8.5kg as an example) are realized.

Actually, when an insulated step 1 having a length of 600 mm, a width of 350 mm, a height of 45 mm and a height of the upper surface of the top plate 2 from the floor of 600 mm was manufactured, a load capacity of 1000 N and a total mass of 8 were actually produced. It was confirmed that a weight reduction of 5.5 kg could be achieved. As a result of hearings with workers, etc., it has been confirmed that the mass is not too light and not too heavy. Further, when the durability of the opening / closing operation of the hinge mechanism 4 was confirmed, it was confirmed that no abnormality was observed even after the opening / closing operation was repeated 10,000 times.

In the above-described embodiment, the metal pipe is adopted as the metal aggregate, but the present invention is not limited to this, and a metal aggregate having another shape can be adopted. As an example, a metal aggregate having a honeycomb shape in a plan view when the top plate portion 2 is viewed from above can be mentioned. It should be noted that the aggregate is not limited to metal as long as it is an equivalent aggregate.

Although the present invention has been described in detail above in accordance with specific embodiments, the present invention in which various substitutions, modifications, changes, etc. regarding the form and details are defined by the description of the claims. It is clear to those with ordinary knowledge in the art that it can be done without departing from the spirit and scope.

1 Insulated step 2 Top plate 3 Legs 4 Hinge mechanism 43 1st hinge vane 44 2nd hinge vane 45 Connecting part 44d 1st locking hole 44e 2nd locking hole 5 Square pipe 6 (61) ~ 64) Wood 7 Lock mechanism 71 Lock pin 72 Elastic member

Claims (5)

A top plate portion in which an outer peripheral surface is formed of an acrylic modified resin and a metal aggregate is arranged in an internal space sealed by the outer peripheral surface.
A pair of ladder-shaped legs that are made of fiber reinforced plastic and support the top plate,
An insulating step made of metal or resin having an insulating coating on the surface, and provided with a hinge mechanism for connecting the legs to the top plate so as to be foldable. The hinge mechanism is a connecting portion that rotatably connects the hinge vane on the top plate side, the hinge vane on the leg side, and the hinge vane on the top plate side and the hinge vane on the leg side. , And a locking mechanism that can be fixed with the legs open and folded.
The lock mechanism includes a lock pin that also serves as an operation unit arranged in a lower region of the top plate portion, a first locking hole that the lock pin engages with and locks when the leg portion is opened, and the leg. The second locking hole comprises a second locking hole that the lock pin engages with and locks when the portion is folded, and an elastic member that urges the lock pin in the locking direction. The insulating step according to claim 1, wherein the lock pin has a curved elongated hole shape that allows the lock pin to engage with the second locking hole even if any of the pair of legs is folded first. In the hinge mechanism, support pieces are provided on the hinge wings on the top plate side and the hinge wings on the leg side, respectively, and when the legs are opened, these support pieces come into contact with each other and the load from the top plate is applied. The insulating step according to claim 2, further comprising a structure for receiving the hinge, and providing a buffer space between the upper end portion of the leg portion and the top plate portion. The metal aggregate of the top plate portion is formed by arranging a plurality of metal pipes in parallel, fixing adjacent metal pipes to each other, and arranging the metal pipes so as to straddle the legs.
The insulating step according to any one of claims 1 to 3, wherein a reinforcing material of wood is arranged inside the metal pipes located at both ends along the length direction of the metal pipes. The fiber reinforced plastic contains glass fiber and a matrix resin, and the fiber reinforced plastic contains glass fiber and a matrix resin.
The insulating step according to any one of claims 1 to 4, wherein the ratio of the glass fiber to the matrix resin is 40 to 45% by mass: 55 to 60% by mass.

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