JP2011214348A - Ladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ladder excellent in workability and productivity.SOLUTION: A pair of supports 22 are formed into a cylindrical shape and is constituted of one pipe respectively. A step 30 includes tread sections 32, fitting sections 34, arch ribs 36, long-sized ribs 37 and short-sized ribs 38. The tread sections 32 are configured in a length stretched between the pair of the supports 22, and top faces are formed into a flat shape. The fitting sections 34 are configured at both ends of the tread sections 32, formed into an approximately cylindrical shape and a pin 52 is formed projecting on the inner wall 34B. When the supports 22 are fitted into the fitting sections 34, the pin 52 is locked with a hole 50 formed in the supports 22, allowing the fitting sections 34 to be fixed to the supports 22.

Description

  The present invention relates to a ladder used in a place where water is stored such as an aquarium.

  In condominiums, tenant buildings, factories, commercial facilities, etc., water tanks for storing drinking water, middle water and the like are installed. Such a water tank is usually provided with a ladder for entering and exiting the water tank for inspection and cleaning. The ladder used here is mainly made of resin from the viewpoint of hygiene and corrosion resistance. In order to further ensure hygiene, water tightness is required so that water does not enter a hollow portion such as a pipe.

  In order to ensure this watertightness, when the ladder is configured by connecting a plurality of pipe parts, the TS method is used for the connection portion. Moreover, in the technique described in Patent Document 1, the connection portion is brought into close contact by blow molding using a mold.

JP 2006-307605 A

  However, since the conventional TS method is used in Patent Document 1, the number of parts increases, and it cannot be said that the workability is sufficient. Moreover, since high component precision is required in order to prevent adhesion failure, it cannot be said that productivity is sufficient.

  This invention is made | formed in view of the said fact, and makes it a subject to provide the ladder excellent in workability and productivity.

  The ladder according to the first aspect of the present invention is a pair of cylinders that are integrally formed with each other, and a strut that is perforated at least at one location along the axial direction of the cylinder, and between the pair of struts A stepped portion that spans between the stepped portion and an end of the stepped portion that surrounds the outer peripheral surface of the column, and an inner wall that faces the outer peripheral surface of the column is provided with a pin that engages with the hole of the column And at least one step having:

  According to the ladder of the present invention as set forth in claim 1, in a state where the support column is fitted into the mounting portion of the step, a hole opened in at least one place in the support column and the mounting portion of the step facing the outer peripheral surface of the support column The pin provided on the inner wall of the unit is coupled. For this reason, the requirement of the positional accuracy of each part is eased compared to the case where the outer peripheral surface of the column and the inner wall of the mounting unit are fixed only by bonding with an adhesive in a state where the column is fitted in the mounting unit of the step. Therefore, it is excellent in productivity and the workability is also excellent because the mounting position of the step to the support column can be determined easily and accurately.

  According to a second aspect of the present invention, in the ladder according to the first aspect, the outer peripheral surface of the support column and the inner wall of the attachment portion are bonded together with an adhesive.

  According to the ladder according to the second aspect of the present invention, since the outer peripheral surface of the support column and the inner wall of the mounting portion of the step are bonded by the adhesive, the support column and the step can be more firmly fixed.

  According to a third aspect of the present invention, in the ladder according to the first or second aspect, the pin is formed at a position on the stepped portion side of the inner wall of the mounting portion.

  According to the ladder of the present invention as set forth in claim 3, since the pin of the step mounting portion is formed at the step portion side portion of the inner wall of the mounting portion, the step is applied to the load acting on the step portion. The bonding strength between the support and the column can be improved.

  As described above, the ladder according to the first aspect of the present invention is excellent in workability and productivity.

  The ladder according to the second aspect of the present invention can more firmly fix the support column and the step.

  The ladder according to the third aspect of the present invention can improve the bonding strength between the step and the column with respect to the load acting on the stepped portion.

It is a perspective view which shows the decomposition | disassembly state of the ladder of one Embodiment in this invention. It is a side view which shows the ladder of one Embodiment in this invention. It is a top view which shows the decomposition | disassembly state of the ladder of one Embodiment in this invention. It is a side view which shows the pin of the ladder of one Embodiment in this invention. It is a bottom view which shows the step of the ladder of one Embodiment in this invention. It is sectional drawing seen from the longitudinal direction which shows the step of the ladder of one Embodiment in this invention. It is sectional drawing which shows the connection part of the upper attachment member and support | pillar of one Embodiment in this invention. It is a perspective view which shows the ladder of one Embodiment in this invention. It is a schematic block diagram which shows the ladder of one Embodiment in this invention, and the water tank in which a ladder is installed. It is a top view which shows the decomposition | disassembly state of the ladder of other embodiment in this invention. It is a top view which shows the decomposition | disassembly state of the ladder of other embodiment in this invention. It is a top view which shows the decomposition | disassembly state of the ladder of other embodiment in this invention. It is a side view which shows the pin of other embodiment in this invention.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 9, the ladder 20 according to the present embodiment is installed in the water tank 10. The water tank 10 is a water tank that is provided in a condominium, a tenant building, a factory, a commercial facility, or the like and stores drinking water, middle water, and the like. Further, the water tank 10 is partitioned into two water storage chambers 14 and 16 by an intermediate partition wall 12.

  Each of the water storage chambers 14 and 16 has inspection ports 14A and 16A, and a ladder 20 is installed from the inspection ports 14A and 16A toward the bottom of the water storage chambers 14 and 16. The same ladder 20 is provided in each of the inspection ports 14A and 16A.

  As shown in FIG. 8, the ladder 20 includes a pair of struts 22, a plurality of steps 30, an upper mounting member 24, and a lower connection member 26. Further, the pair of support columns 22 are formed in a cylindrical shape, and each of them is integrally formed without a joint, that is, each of them is constituted by a single pipe. In addition, a pair of support | pillar 22 is arrange | positioned mutually parallel to the perpendicular direction. The ladder 20 is made of polyvinyl chloride or the like.

  An upper mounting member 24 is connected to the upper end of the column 22. The upper mounting member 24 has a cylindrical shape in which one end side can insert the support column 22 (hereinafter referred to as “upper connecting cylindrical portion 24A”), and the other end side has a flat plate shape along the inner walls of the water storage chambers 14 and 16 (hereinafter referred to as “upper side”). Mounting flat plate portion 24B ").

  As shown in FIG. 7, the inner wall of the upper connecting cylindrical portion 24A is tapered so that the opening side has a large diameter, and the upper mounting member 24 and the column 22 have the upper end of the column 22 connected to the upper connecting cylindrical portion 24A. And connected by TS method. A hole 23 is formed in the upper mounting flat plate portion 24B, and is attached to the inner walls of the water storage chambers 14 and 16 by mounting members such as bolts (not shown).

  As shown in FIG. 8, a lower connection member 26 is connected to the lower end of the support column 22. The lower connection member 26 is U-shaped, and both ends of the U-shape are formed into a cylindrical shape into which the support 22 can be inserted, and are bent in a direction approaching the inner walls of the water storage chambers 14 and 16 (hereinafter referred to as “lower connection cylindrical portion 26A”). The intermediate portion 26B is bent in a U shape. The inner wall of the lower connecting cylindrical portion 26A is tapered so that the open side has a large diameter, like the upper connecting cylindrical portion 24A. The lower connecting member 26 and the support column 22 connect the lower end of the support column 22 to the lower side. It is inserted into the cylindrical portion 26A and connected by the TS method.

  As shown in FIGS. 1 and 2, the step 30 includes a step portion 32, a mounting portion 34, an arch rib 36, a long rib 37, and a short rib 38. In addition, the step portion 32 is configured to have a length that spans between the pair of support posts 22 and has a flat upper surface, and the step portion 32 extends in a direction orthogonal to the support posts 22 between the pair of support posts 22. Has been placed. Note that an anti-slip protrusion 32A is formed on the upper surface of the tread 32.

  The attachment portion 34 is configured at both ends of the step portion 32. The attachment portion 34 has a substantially cylindrical shape, and the lower side from the intermediate portion in the axial direction is cut away from the step portion 32 (on the outer side of the end portion) to have a semicircular cross section. This notched portion is not necessarily required, and the attachment portion 34 may be cylindrical with respect to the lower portion. In addition, the inside of the cylinder of the attachment portion 34 is a fitting space 35.

  As shown in FIG. 3, the inner diameter 34 </ b> A of the attachment portion 34 is slightly smaller than the outer diameter 22 </ b> A of the support 22 when not attached to the support 22. Therefore, when the support column 22 is fitted into the fitting space 35, the mounting portion 34 is expanded in the direction in which the fitting space 35 is expanded. Further, the inner diameter 34 </ b> A of the attachment portion 34 is set in consideration of the elasticity of the attachment portion 34 and the adhesion of the attachment portion 34 to the column 22.

  The inner diameter 34 </ b> A of the attachment portion 34 is not necessarily smaller than the outer diameter 22 </ b> A of the support column 22, and may be the same size.

  The attachment portion 34 is formed with an opening 34 </ b> C in which a side wall is notched across both axial ends. The two openings 34 </ b> C at both ends of the attachment portion 34 are opened in the same direction (downward in FIG. 3) in the direction orthogonal to the longitudinal direction of the stepped portion 32. The opening 34C has a width size 34D that allows the column 22 to be fitted into the fitting space 35 via the opening 34C. That is, the width size 34D of the opening 34C is set according to the amount of bending deformation of the attachment portion 34, the outer diameter 22A of the support column 22, the inner diameter 34A of the attachment portion 34, and the like. In consideration of the holding force when the support column 22 is fitted into the fitting space 35, the central angle θ1 of the opening 34C is preferably 90 ° or less.

  As shown in FIG. 1, each strut 22 has a hole 50 at least at one location along its axial direction. More specifically, each column 22 has a plurality of holes 50 at predetermined intervals along the axial direction. In the pair of columns 22, each column 22 is located at the same position from each axial end. Each hole 50 is formed. That is, the pair of struts 22 are the same.

  As shown in FIG. 3, a pin 52 that engages with the holes 50 of the pair of struts 22 is integrally formed in the step 30. The pin 52 is formed to project toward the center P <b> 1 of the mounting portion 34 at a portion 34 </ b> F on the stepping portion 32 side in the inner wall 34 </ b> B of the mounting portion 34 that faces the outer peripheral surface of the column 22. The position of the pin 52 on the inner wall 34B of the attachment portion 34 is substantially the center portion in the width direction of the step 30. More specifically, the position of the pin 52 passes through the center P1 of the attachment portion 34 and is parallel to the axis of the step portion 32. It is on the line 32B which extends to. As shown in FIG. 2, the axial position (vertical position) of the column 22 of the pin 52 coincides with the lower surface 37 </ b> A of the long rib 37.

  As shown in FIG. 4, the root portion 56 of the pin 52 has a cylindrical shape. Moreover, the front-end | tip part 58 of the pin 52 is provided with the column-shaped part 58A and the cone-shaped part 58B gradually reduced in diameter from this column-shaped part 58A. Further, a neck portion 60 having a diameter reduced from the root portion 56 toward the tip portion 58 is formed between the root portion 56 of the pin 52 and the cylindrical portion 58 </ b> A of the tip portion 58.

  A slit 62 is formed in the pin 52 from the distal end portion 58 toward the root portion 56. The tip 62A of the slit 62 reaches the vicinity of the root portion 56 in the neck 60 of the pin 52, and the tip 62A is semicircular. The slit 62 passes through the shaft center 52A of the pin 52 and crosses the pin 52 in the radial direction.

  Therefore, the tip portion 58 of the pin 52 is divided into two engagement pieces 58C and 58D by the slit 62. Further, the two engaging pieces 58C and 58D of the tip portion 58 of the pin 52 are elastically deformed in a direction approaching each other (in the direction of arrow A in FIG. 4).

  The outer diameter R1 of the tip portion 58 of the pin 52 is larger than the diameter R2 of the hole 50 of the column 22, and the outer diameter R3 of the root portion 56 of the pin 52 is smaller than the diameter R2 of the hole 50 of the column 22. It has become.

  Therefore, when the pin 52 is inserted into the hole 50 of the column 22, the tip 58 of the pin 52 slides with the inner periphery of the hole 50, so that the two engaging pieces 58C and 58D approach each other (FIG. 4). The tip portion 58 of the pin 52 passes through the hole 50 of the support post 22.

  Further, when the tip portion 58 of the pin 52 passes through the hole 50 of the support column 22 and the root portion 56 and the neck portion 60 of the pin 52 are inserted into the hole 50, the two engagements of the tip portion 58 of the pin 52 are performed. The pieces 58C and 58D return to their original positions. For this reason, the engagement pieces 58 </ b> C and 58 </ b> D of the pin 52 are engaged with the outer peripheral portion of the hole 50 of the column 22. In this way, the step 30 can be fixed to the pair of struts 22 by engaging the pins 52 at both ends of the step 30 with the holes 50 of the pair of struts 22, respectively.

  As shown in FIGS. 2 and 5, plate-shaped arch ribs 36, long ribs 37, and short ribs 38 are formed on the lower surface of the tread portion 32. The step portion 32, the attachment portion 34, the arch rib 36, the long rib 37, and the short rib 38 are integrally formed. Step 30 including these members can be made of a resin material such as polyvinyl chloride resin.

  The arch rib 36 is disposed in the center portion in the width direction below the step portion 32 so as to cross between one attachment portion 34 and the other attachment portion 34. The arch rib 36 has an arc shape (arch shape) in which the length in the vertical direction at one end and the other end is the longest and the length in the vertical direction at the center is the shortest. In addition, one end and the other end of the arch rib 36 are integrally connected to the attachment portion 34.

  Two long ribs 37 are arranged in parallel on both sides of the arch rib 36 with the arch rib 36 interposed therebetween. The length of the long rib 37 in the vertical direction is substantially the same as the shortest portion of the arch rib 36. Further, the short ribs 38 are arranged at three places in the width direction below the step portion 32.

  As shown in FIG. 6, the short rib 38 is disposed from each of the two long ribs 37 to the arch rib 36 and has an arch shape in which the thickness of the central portion is reduced.

  As shown in FIG. 9, in step 30, one attachment portion 34 is attached to one side of the pair of struts 22, and the other attachment portion 34 is attached to the other side of the pair of struts 22. It is spanned between 22 in the direction orthogonal to the column 22. In addition, a plurality of steps 30 (five in this embodiment) are attached to the pair of support posts 22 at predetermined intervals in the axial direction of the support posts 22.

  Next, the installation method which installs the ladder 20 of the said structure in the water storage chambers 14 and 16 of the water tank 10 is demonstrated.

  First, the two support columns 22 are arranged in parallel at a predetermined interval, and the upper attachment member 24 is connected to the upper end of each support column 22 and the lower connection member 26 is connected to the lower end thereof by the TS method. Specifically, the connection between the support column 22 and the upper mounting member 24 is performed by applying an adhesive to the outer peripheral surface of the upper end of the support column 22 and the tapered portion inside the upper connection cylindrical portion 24A, and the upper end of the support column 22 is connected to the upper connection cylindrical portion. The connecting portion is cured for a period of time until it is inserted into 24A and the bonding by the adhesive 39 is completed. Further, the connection between the support column 22 and the lower connection member 26 is performed by applying an adhesive to the outer peripheral surface of the lower end of the support column 22 and the tapered portion inside the lower connection cylindrical portion 26A, and inserting the lower end of the support column 22 into the lower connection cylindrical portion 26A. Then, the connection part is cured for a time until the adhesive bonding is completed.

  Next, the plurality of steps 30 are attached to the pair of support posts 22 at predetermined intervals. In addition, attachment to the support | pillar 22 of each step 30 is performed as follows.

  The strut 22 is fitted into the fitting space 35 of the mounting portion 34 in step 30. At this time, when the pin 52 is inserted into the hole 50 of the support column 22, the two engagement pieces 58C and 58D of the tip portion 58 of the pin 52 are elastically deformed in a direction in which they approach each other (direction of arrow A in FIG. 4). The tip portion 58 of the pin 52 passes through the hole 50 of the column 22. Further, when the tip portion 58 of the pin 52 passes through the hole 50 of the support column 22 and the root portion 56 and the neck portion 60 of the pin 52 are inserted into the hole 50, the two engagements of the tip portion 58 of the pin 52 are performed. The pieces 58C and 58D return to their original positions. For this reason, the engagement pieces 58 </ b> C and 58 </ b> D of the pin 52 engage with the outer peripheral portion of the hole 50 of the column 22. As a result, step 30 can be fixed to the pair of struts 22.

  In addition, watertightness can also be ensured by assembling the pin 52 after fitting the packing.

  And the ladder 20 is installed in the water storage chambers 14 and 16 of the water tank 10 by fixing the ladder 20 to the inner walls of the water storage chambers 14 and 16 through the holes 23 of the upper mounting member 24.

  As described above, in the present embodiment, in a state where the support column 22 is fitted into the attachment portion 34 of step 30, the hole 50 formed in the support column 22 and the pin formed to protrude from the inner wall 34B of the attachment portion 34 of step 30 are formed. 52 is engaged. For this reason, compared with the case where the outer peripheral surface of the support column 22 and the inner wall 34B of the mounting portion 34 are fixed only by bonding with an adhesive in a state in which the support column 22 is fitted in the mounting portion 34 of step 30, The requirement for positional accuracy of the 30 attachment portions 34 is relaxed. As a result, in the ladder 20 of this embodiment, the column 22 and the step 30 can be easily manufactured, and the productivity is excellent.

  Moreover, in this embodiment, since the attachment position to the support | pillar 22 of step 30 is decided by the hole 50 formed in the support | pillar 22, compared with the case where an adhesive agent is used, the attachment position to the support | pillar 22 of step 30 is set. Easy and accurate. As a result, it can be easily assembled and has excellent workability.

  In the present embodiment, since the holes 50 are formed at equal intervals along the axial direction of the support column 22 at the time of construction, the positions of both ends of the step 30 are accurately determined. As a result, the step 30 can be fixed to the column 22 without tilting left and right.

  Further, in the present embodiment, the pin 52 of the attachment portion 34 in step 30 is formed in a portion on the step portion 32 side in the inner wall 34B of the attachment portion 34. For this reason, the attachment part 34 is hard to be damaged by the load which acts on the step part 32 of step 30 at the time of use of the ladder 20, and the joint strength of the support | pillar 22 and step 30 can be improved.

  Moreover, in this embodiment, since the support | pillar 22 is comprised with one pipe | tube, compared with the case where many components are connected, watertightness is ensured more.

(Other embodiments)
Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, in the above-described embodiment, the inner wall 34B of the attachment portion 34 and the outer peripheral surface of the portion attached to the attachment portion 34 of the support column 22 are further bonded via an adhesive to further strengthen the support column 22 and step 30. It may be fixed to.

  As the adhesive, a polyvinyl chloride resin adhesive such as a mixed liquid of cyclohexanone, tetrahydrofuran, methyl ethyl ketone, and polyvinyl chloride chlorinated product can be used.

  Moreover, in the said embodiment, although the pin 52 was formed in the site | part 34F by the side of the step part 32 in the inner wall 34B of the attaching part 34 of the support | pillar 22, the pin 52 does not necessarily need to be formed in this position and the inner wall of the attaching part 34 Any position of 34B may be used. For example, as shown in FIG. 10, a pin 52 may be provided toward the center P1 of the mounting portion 34 at a position 34G facing the opening 34C of the inner wall 34B in the mounting portion 34 of step 30. In particular, by setting this position, when attaching the step 30 to the support column 22, the operator can attach the step 30 without changing the width of the pair of support columns 22, and the installation operation can be performed smoothly.

  Moreover, in the said embodiment, although 34 C of opening comprised in the attachment part 34 of the both ends of step 30 was opened in the same direction toward the direction orthogonal to the longitudinal direction of the step part 32, opening 34 C is It is not always necessary to configure in this direction, and as shown in FIGS. 11 and 12, the opening 34 </ b> C may be opened toward the outside (both ends) of the step 30 in the longitudinal direction.

  In the above embodiment, as shown in FIG. 4, the slits 62 are formed in the pin 52 from the tip 58 to the root 56. Instead, the slit is formed in the pin 52 as shown in FIG. It is good also as a structure which does not form. In this case, the distal end portion 58 is contracted by elastic deformation, so that the distal end portion 58 of the pin 52 passes through the hole 50 of the column 22 and the distal end portion 58 of the pin 52 is engaged with the outer peripheral portion of the hole 50. Match.

DESCRIPTION OF SYMBOLS 10 Water tank 20 Ladder 22 Ladder post 30 Ladder step 32 Step step part 34 Step attachment part 34B Inner wall of attachment part 34C Opening of attachment part 50 Strut hole 52 Pin of attachment part 56 Pin base part 58 Pin tip Part 60 Pin neck 62 Pin slit

Claims (3)

A pair of cylinders, each integrally formed, and a column having a hole in at least one place along the axial direction of the cylinder,
A tread spanned between the pair of struts, and a pin that is formed on both ends of the tread to surround the outer peripheral surface of the strut and engages with a hole in the strut on an inner wall facing the outer peripheral surface of the strut And at least one step comprising:
With ladder.   The ladder according to claim 1, wherein an outer peripheral surface of the support column and an inner wall of the attachment portion are bonded with an adhesive.   The ladder according to claim 1 or 2, wherein the pin is formed in a portion on the step portion side in an inner wall of the attachment portion.

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