JP2010185261A - Main-rope support - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a main-rope support which is reduced in weight of a main-rope support body and has a stress concentration section provided to the support body without forming either rugged parts or recessed parts on the side of the main-rope support body. <P>SOLUTION: The main-rope support includes the support body, a main-rope retaining fitting mounted to the upper end of the support body, and a fixing member for being fixed to the flange of a steel beam. The support body includes a lower sleeve tube comprising a tapered tube with its width narrowing upward in cross section and an upper core tube which can be inserted inside the sleeve tube to be fixed thereto. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a flange portion of a steel beam for bridging a master rope that hooks a hook provided at the tip of a safety belt attached to a worker's waist for the purpose of ensuring the safety of work at height in a building under construction. It is related with the master rope support which stands up.

  Conventionally, as a master rope support attached to the flange portion of a steel beam, a support pillar body made of a square tube having a rectangular or square cross section, and a fixing bracket such as a vise provided at the lower end of the support pillar body, It is common to have a main rope holding bracket attached to the upper end of the column main body, and hold and fix it to the upper flange of a steel beam made of H-shaped steel etc. with a fixing bracket such as a vise The standing line was set up. Two or more master ropes are attached to one steel beam, and the master rope is bridged between the adjacent master ropes via each master rope holding bracket.

  As a result, the worker accidentally steps off the steel beam by hooking the hook provided at the tip of the safety belt attached to the waist to the master rope spanned between adjacent master rope struts. Even if it falls from the steel beam, the safety belt is retained by the master rope, so there is no fear of dropping from the steel beam to the ground, and it is possible to safely work at a high place. In addition, the worker walks to the master rope along the master rope spanned between the master rope struts, removes the hook hooked on the master rope, and next to the next master rope strut. After hooking the master rope again, he walks between the next master rope supports. Here, the hook has a lock mechanism, and is locked during walking along the parent rope.

  Here, there are two types of master rope support, “parallel type” and “orthogonal type”. These are properly used as follows according to the location of the master rope support on the steel beam.

  "Parallel type" master rope columns are erected on the side edge on the same side in the longitudinal direction of the steel beam, but are used when a load acts only in the direction parallel to the steel beam, The direction in which the master rope attached to one “parallel type” master rope is stretched is parallel to the steel beam. Therefore, the “parallel type” master rope support may be manufactured from a square tube having a square cross section, but may be manufactured from a square tube having a rectangular cross section. Note that the “parallel” master rope strut manufactured from a rectangular tube with a rectangular cross-section has a cross-section with the long side in the parallel direction where the load acts and the short side in the right-angle direction where the load does not act. It is installed and used.

  In addition, in the “parallel type” master rope support, at the corner where the two steel beams are orthogonal, the “parallel type” master rope support is placed at each of the locations where it hits the end face of the master rope stretched on each steel beam. It is necessary to set up. In other words, it is not possible to stand and use one “parallel type” master rope support, so it is necessary to install two “parallel” master rope supports at the corner where two steel beams are orthogonal. is there.

  On the other hand, the “orthogonal” master rope support is disposed and fixed at a corner portion where two steel beams are orthogonal. Since the master rope attached to one “orthogonal” master rope is stretched not only in the direction parallel to the steel beam but also in the direction perpendicular to it, the “orthogonal” master rope has a direction parallel to the steel beam. In addition to this, the load also acts in the perpendicular direction. Therefore, the “orthogonal” parent rope support is usually made of a square tube having a square cross section so as to have the same rigidity in both the parallel and perpendicular directions.

  When using an “orthogonal” master brace, one “orthogonal” master brace can be used as a single “orthogonal” parent brace at the corner where two steel beams are orthogonal. There is an advantage that only installation is required. Also, when one steel beam is installed at a right angle to two parallel steel beams and the length of one steel beam installed at a right angle is short (10 m or less) In that one short steel beam, there is no need to set up a main brace, especially between the “orthogonal” main struts erected on each of two parallel steel beams. By stretching the master rope, there is an advantage that the master rope can be stretched with respect to the one short steel beam.

  The “orthogonal” master rope support can also be used as a “parallel” master rope support and is sometimes referred to as a “combination” master rope support.

  The main rope brace is tilted in the direction away from the steel beam toward the upper end of the pillar body so that the parent rope holding bracket projects to the outside of the steel beam. Since the position protrudes outward from the steel beam and the worker can take a large space for walking, it is possible to secure a safe passage without hindering walking on a small beam having a narrow steel flange width.

  By the way, in the conventional master rope support, regardless of the parallel type or the orthogonal type, when the worker falls from the steel beam, a hook provided at the tip of the safety belt attached to the operator's waist is provided. A large impact load corresponding to the weight of the worker acts on the hooked master rope in the vertical direction, pulling force acts on the parent rope, and the parent rope is arranged on the left and right with the worker who has fallen as the center. A force is generated that pulls the master rope holding metal fittings at the upper end of the master rope support. Therefore, a large bending stress acts on the lower end of the column main body that hits the joint between the fixing bracket and the column main body, the fixing bracket breaks, and the master rope column falls off the steel beam, or the column main body is bent from the root. There was a fear. As a result, when the fixing bracket is broken, as well as when the support main body is bent from the root, the master rope hangs down to near the steel beam or further downward, and as a result, the operator's fall distance increases. There is a risk that a large impact force may be applied to the worker himself, or that the worker may be struck against a steel beam or other structure, resulting in a major accident.

  For this reason, in Patent Document 1, as the master rope support, by forming an uneven portion in the middle side of the column main body having a square cross section, and by forming a recess in the middle of the other side, It has been proposed to provide a stress concentration part in the middle of the column body. By providing such a stress concentration part, even if an operator falls from the steel beam and a large force is applied in the lateral direction to the main rope column, the stress concentration part provided in the middle of the main rope column body Since the stress acts on the main strut main body, the main strut main body will be bent from the stress concentration part provided in the middle, so there is a risk that the main strut main body will be bent from the root or the fixing bracket may be damaged. It is going to be smaller. In addition, the main rope support body will be bent in the middle rather than its root, so the main rope will not droop greatly from the original position, and the impact force of the operator's fall is necessary for bending at the stress concentration part. Because it absorbs with a lot of energy, the impact force applied to the worker is so small that it is possible to avoid a major accident.

Japanese Patent No. 3853780

  However, in the master rope support described in Patent Document 1, a support body is formed by forming an uneven portion on one side of the middle of the support body having a square cross section and forming a recess on the other side. In the middle, a stress concentration part is provided, and for this reason, it is necessary to perform complicated pressing using a dedicated die.

  Moreover, since the square tube which has a cross section of the same width over the full length of a support | pillar main body is used, there exists a problem that the weight of a master rope support | pillar becomes large.

  An object of the present invention is to reduce the weight of the master rope support body and to provide a stress concentration portion on the support pillar body without forming any irregularities and recesses on the sides of the parent rope support body. Is to provide.

  The inventors of the present invention have studied a master rope strut that has a stress concentrating portion in the pillar main body and can be reduced in weight without forming any irregularities and recesses on the side of the parent rope pillar main body. Repeated. As a result, the following findings (a) to (f) were obtained.

  (a) When an operator falls from a steel beam, a hook provided at the tip of a safety belt attached to the operator's waist, a parent rope on which the hook is hooked, and a parent holding the parent rope An impact load corresponding to the weight of the operator acts diagonally downward on the top of the main rope support body through the rope holding bracket. However, the bending moment due to this impact load is small at the top of the parent rope support and acts largely at the root. Therefore, if the entire length of the master rope support main body is composed of square tubes having the same width, the root portion has an appropriate strength design, but the top portion has an excessive strength design.

  In order to avoid this, the master rope support main body may be constituted by a tapered tube whose cross section becomes narrower toward the top. In other words, the bending moment due to the impact load at the time of dropping gradually decreases from the base part to the top part of the main rope column body. If a taper tube with a narrow width is employed, it is possible to design an appropriate strength from the root to the top of the main rope support body. Moreover, since the weight of the master rope support | pillar main body can be reduced by employ | adopting such a taper pipe, the weight reduction of a master rope support | pillar is attained.

  (b) Next, in order to form a stress concentration part in the strut body without forming any irregularities or recesses on the side of the main strut strut body, What is necessary is just to form the part where an area changes rapidly. And in order to change the cross-sectional area of a support | pillar main body rapidly, it is not necessary to form from one continuous taper pipe. The parent strut main body need only be composed of a lower sheath tube made of a tapered tube having a narrower cross section toward the upper side, and an upper core tube that can be inserted and fixed inside the sheath tube. At this time, the lower sheath tube can be provided with an inclination angle in a direction away from the steel beam toward the upper end portion of the column main body.

  A master brace support column can be manufactured by providing a fixing bracket such as a vise at the lower end of the lower sheath tube and providing a master rope holding bracket at the upper end of the upper core tube. In addition, a handle can be attached to the side surface of the lower sheath tube so that the parent rope support can be handled conveniently. Furthermore, a width adjustment member is attached to the side surface of the end portion of the upper core tube, and a plurality of master rope support columns are placed sideways while a part of the upper core tube is accommodated in the lower sheath tube. In this state, the height of the end portion of the upper core tube and the height of the fixing member can be made uniform, so that it is possible to store and transport a plurality of master rope struts with less waste of space. Can do.

  In this way, since the main rope column main body forms a stress concentration portion at the core tube portion directly above the upper end of the sheath tube, when the operator falls, the main rope column main body starts from the core tube portion directly above the upper end of the sheath tube. It will be bent. In addition, since the core tube portion directly above the upper end of the sheath tube is smaller than the cross-sectional width of the sheath tube at the lower part of the main rope column main body, it becomes easy to bend, so the core tube portion immediately above the upper end of the sheath tube is bent. The amount of elastic deformation increases, and the impact load acting on the dropped operator can be reduced accordingly.

  (c) Here, as a cross-sectional shape of the tapered tube used for the lower sheath tube, not only a quadrangle but also a circle can be adopted. Moreover, polygons other than a rectangle may be sufficient. For example, a taper tube is cut into a trapezoidal shape from a plate-like material and then line-welded between both sides, or a square tube or a circular tube having the same outer diameter is drawn with a press and a die. Alternatively, it can be formed by spinning using a forming roller. Moreover, as the material, a metal material such as steel or aluminum can be used.

  In addition, the lower sheath tube of the “orthogonal” master rope brace should have the same rigidity in both the parallel and perpendicular directions with respect to the longitudinal direction of the steel beam. Or it is good to manufacture from a perfect circular tube. The lower sheath tube of the “parallel type” parent rope column may be manufactured from a square tube having a regular polygonal cross section or a square tube having a square shape having a rectangular cross section. It may be manufactured from a circular tube.

  (d) Next, as described above, a tapered tube may be used as the upper core tube that can be inserted and fixed inside the sheath tube, but a straight tube may also be used. Further, as the cross-sectional shape, not only a quadrangle but also a circle can be adopted. Moreover, polygons other than a rectangle may be sufficient. Further, as the material of the upper core tube, the same metal material as the lower sheath tube, such as steel or aluminum, can be used, or a material different from the lower sheath tube may be used. In this case, if a material that is more flexible than the lower sheath tube is used as the material of the upper core tube, the impact load acting on the dropped operator can be further reduced.

  Note that the upper core tube of the “orthogonal” master rope brace should have the same rigidity in both the parallel and perpendicular directions to the longitudinal direction of the steel beam. Or it is good to manufacture from a perfect circular tube. The upper core tube of the “parallel type” parent rope support may be manufactured from a square tube having a regular polygonal cross section or a square tube having a regular circular shape, or a rectangular tube having a rectangular cross section or an elliptical shape. It may be manufactured from a circular tube.

  (e) And in order to make the upper core tube insertable and fixable inside the lower sheath tube, the upper core tube is fitted inside the lower sheath tube, and then a pin or bolt What is necessary is just to fix using a nut etc. For this purpose, the inner shape of the upper end portion of the sheath tube and the outer shape of the lower end portion of the core tube need only be the same.For example, only the upper end portion of the sheath tube is a straight tube shape and the connection portion with the core tube is provided. What is necessary is just to enable it to insert the lower end of the straight pipe | tube-shaped core pipe which forms and has the external shape fitted to the internal shape of this connection part. As described above, when the main strut support body is composed of the lower sheath tube and the upper core tube that can be inserted and fixed inside the sheath tube, when the main strut support is stored and transported in a warehouse or the like, The core tube can be accommodated in the sheath tube, and the core tube can be pulled out and fixed when installed on the steel beam. At this time, it is preferable to provide a stopper so that the upper core tube does not enter the lower sheath tube and so that the upper core tube does not come off the lower sheath tube. In addition, it can replace with a stopper by devising arrangement | positioning of a pin or a volt | bolt nut, etc.

  (f) In this way, the main strut main body is composed of the lower sheath tube composed of a tapered tube having a narrower cross section upward, and the upper core tube that can be inserted and fixed inside the sheath tube. Then, a part of the core tube can be accommodated in the sheath tube when the master rope support is stored in a warehouse or transported, and the core tube can be pulled out and fixed when installed on the steel beam. Therefore, it takes no space for storage and transportation, so that storage costs and transportation costs can be saved. In addition, when the upper core tube is bent due to an operator's drop or impact during transportation, only the bent upper core tube needs to be replaced, so that the repair cost can be reduced.

  The present invention has been made on the basis of the above findings, and the gist thereof resides in the parent braces (1) to (5) below.

  (1) A main strut strut comprising a strut main body, a main rope holding bracket attached to the upper end of the main strut body, and a fixing member for fixing to the flange portion of the steel beam. A parent strut comprising: a lower sheath tube made of a tapered tube having a narrow cross section; and an upper core tube insertable and fixable inside the sheath tube.

  (2) The master rope support of (1) above, wherein a width adjusting member is attached to a side surface of an end portion of the upper core tube.

  (3) The parent strut according to (1) or (2) above, wherein the lower sheath tube is provided with an inclination angle in a direction away from the steel beam toward the upper end of the strut body.

  (4) The parent rope strut according to any one of (1) to (3) above, wherein the lower sheath tube has a quadrangular cross-sectional shape.

  (5) The parent rope strut according to any one of (1) to (3) above, wherein the cross-sectional shape of the lower sheath tube is circular.

  In the master rope support according to the present invention, the support main body is reduced in weight, and the core pipe portion directly above the upper end of the lower sheath pipe is formed without forming any irregularities or recesses on the side of the support main body. If a stress concentrating part with a small area is provided and the operator falls from the steel beam, the main strut strut body can be bent at the core pipe part of the stress concentrating part to absorb energy. It is possible to reduce the impact load acting on the. In addition, since the core tube can be accommodated in the sheath tube, it does not take up space during storage and transportation, and repair when the column main body is bent is easy. Furthermore, since it is not necessary to perform complicated press work for forming the concavo-convex part and the concave part on the side of the column main body, a dedicated mold is not necessary, and the manufacturing cost can be reduced.

It is an example of the master rope support | pillar which concerns on this invention. (a) is a front view and (b) is a right side view. When the worker walks on the flange of the steel beam on which the master rope column according to the present invention is erected, the hook provided at the tip of the safety belt attached to the operator's waist is bridged between the master rope columns. It is a front view which shows an example of the state hooked on the made master rope. It is a front view which shows an example of the state of a master rope and a master rope strut when an operator should fall from a steel beam. It is an example when the upper core pipe of the master rope support is accommodated in the lower sheath pipe. (a) is a front view and (b) is a right side view. It is a top view which shows the orderly state before binding a some master rope support | pillar for conveyance in the state which accommodated the upper core pipe in the lower sheath pipe. It is another example of the master rope support | pillar which concerns on this invention. (a) is a front view, (b) is a right side view, and (c) is a cross-sectional view (enlarged view) taken along line AA. It is an example when the upper core pipe of the master rope support | pillar shown in FIG. 6 is accommodated in a lower sheath pipe. (a) is a front view and (b) is a right side view.

  Hereinafter, the master rope support | pillar which concerns on this invention using drawing is demonstrated. The present invention is not limited to the following examples.

  FIG. 1 is an example of a master rope support according to the present invention. (a) is a front view and (b) is a right side view.

  This master rope 1 is composed of a pillar main body, a master rope holding metal fitting 10 attached to the upper end of the pillar main body, and a fixing member 5 for fixing to a flange portion of a steel beam made of H-shaped steel.

  The strut body is composed of a lower sheath tube 2a made of a tapered tube having a circular cross section with a narrower cross section upward, and an upper core tube 2b that can be inserted and fixed inside the sheath tube 2a. The upper core tube 2b is made of a straight tube having a perfectly circular cross section. And the connection part 2c which consists of a straight pipe of a cross-sectional round shape is provided in the upper end part of the sheath pipe 2a so that the lower end part of the core pipe 2b may be fitted and inserted in it.

  The side surface of the upper core tube 2b has a total of four holes including two lower holes 4a in the vicinity of the lower end and two upper holes 4b in the middle. It is installed in a state of being biased outward. That is, a lower pin 3a is installed inside each of the two lower holes 4a near the lower end, and an upper pin 3b is installed inside each of the middle two upper holes 4b. The spring steel 8 attached to the inside of 2b is urged outward so that the heads of the upper pin 3a and the lower pin 3b come out of the respective holes.

  The connecting portion 2c has two holes 4c, and the two lower pins 3a provided near the lower end of the side surface of the upper core tube 2b have two heads drilled in the connecting portion 2c. From the hole 4c. Since the two lower pins 3a are urged outward by spring steel, the lower pins 3a must be separated from the two holes 4c formed in the connecting portion 2c unless the head of the lower pins 3a is pressed by human power. There is no.

  In this way, the upper core tube 2b is pulled out to the maximum from the lower sheath tube 2a by taking out the head of the lower pin 3a of the upper core tube 2b from the two holes 4c drilled in the connecting portion 2c. Can be fixed in the state. Here, the pin itself serves as a stopper.

  The column body is erected and fixed on the flange portion of the steel beam with an inclination angle of 10 ° in the direction away from the steel beam toward the upper end of the column body. The pipe 2a is joined by welding in an inclined state with respect to the fixing member 5 by 10 °. The fixing member 5 has a vise structure and has a U-shaped curved portion when viewed from the side. A lower fixing plate 6 is provided on the lower surface of the U-shaped curved portion, and a mounting bolt 7 is provided on the upper surface. The fixing member 5 can be fixed to the flange portion of the steel beam by fitting the flange portion of the steel beam on the lower fixing plate 6 and tightening the mounting bolt 7 from above. Here, 10 ° is adopted as the inclination angle in the direction away from the steel beam toward the upper end of the column main body, but the inclination angle in the direction away from the steel beam toward the upper end of the column main body is 5 ° to 20 °. Can be selected as appropriate. Further, the lower sheath pipe 2a of the column main body may be joined to the U-shaped fixing member 5 by welding in an upright state without adopting an inclination angle.

  Furthermore, a handle 15 is attached to the side surface of the lower sheath tube 2a so that the main rope support 1 can be easily handled during transportation and storage. In addition, a width adjusting member 17 is attached to the side surface of the end portion of the upper core tube, and the height of the end portion of the upper core tube 2b is set in a state where a plurality of the master rope support columns 1 are placed sideways. And the height of the fixing member 5 can be made uniform.

  FIG. 2 shows a hook provided at the tip of a safety belt attached to the operator's waist when the operator walks on the flange of the steel beam on which the master rope column shown in FIG. It is a front view which shows an example of the state hooked on the master rope spanned between the rope braces.

  The flange portion 20a of the steel beam 20 is fitted into the U-shaped curved portion of the fixing portion 5 of the master rope support 1 shown in FIG. 1, and then the mounting bolt 7 is tightened on the flange portion 20a of the steel beam 20 Thus, the two master rope support columns 1 are erected and fixed to the flange portion 20a of the steel beam 20. The master rope 30 is bridged by connecting the master rope holding bracket 10 attached to the upper end of each master rope support 1.

  The operator 31 is in a state of walking along the master rope 30 after hooking the hook 33 provided at the tip of the safety belt 32 attached to the waist to the master rope 30 and locking (not shown). The operator 31 can walk on the flange 20 a of the steel beam 20 along the master rope 30.

  FIG. 3 is a front view showing an example of the state of the master rope and the master rope when the worker in the state of FIG. 2 falls from the steel beam.

  When the operator 31 mistakenly drops his / her foot from the steel beam 20 and falls, an impact load corresponding to the weight of the operator 31 acts on the parent rope 30 in a vertical direction, and the parent rope 30 has a tensile force. The force which draws the master rope holding | maintenance metal fitting 10 attached to the upper end of the master rope support | pillar 1 toward each other generate | occur | produces.

  However, the master rope column 1 is composed of a lower sheath tube 2a having a tapered tube and a lower core tube 2b inserted and fixed inside the sheath tube, and the lower sheath tube 2a. Since the stress concentration part with a small cross-sectional area is provided in the core tube part directly above the upper end of the steel pipe, when the operator falls from the steel beam, the main strut main body bends at this stress concentration part. The fall distance of the person can be short. Moreover, since the cross-sectional area of this stress concentration part is small, it becomes easy to bend, so that the amount of elastic deformation before the core tube part just above the upper end of the sheath tube is bent increases. Therefore, the impact load acting on the dropped operator can be reduced.

  And the repair of the bent main rope supporter in this way is only necessary to replace the bent upper core tube 2b.

  FIG. 4 is an example when the upper core tube of the master rope support shown in FIG. 1 is accommodated in the lower sheath tube. (a) is a front view and (b) is a right side view.

  From the state shown in FIG. 1, the upper core tube 2 b is pushed down from the hole 4 c formed in the connection portion 2 c while the heads of the two lower pins 3 a of the upper core tube 2 b are pressed by human power. The core tube 2a is pushed into the upper core tube 2b, and then the heads of the two upper pins 3b of the upper core tube 2b are taken out from the hole 4c formed in the connecting portion 2c, thereby the upper core tube is removed from the lower sheath tube 2a. 2b can be fixed in a state of being pulled out to the minimum. Again, since the two upper pins 3b are urged outward by the spring steel 8, unless the head of the upper pin 3b is pressed by human power, the two holes 4c drilled in the connecting portion 2c are used. Since the pin does not come off, the pin itself serves as a stopper.

  FIG. 5 is a top view showing an orderly state before a plurality of parent rope struts in a state where the upper core tube is accommodated in the lower sheath tube are bound for transportation.

  A width adjusting member 17 is attached to the side surface of the end portion of the upper core tube 2b, and a plurality of master rope columns 1 in a state in which a part of the upper core tube 2b is accommodated inside the lower sheath tube 2a. Since the height of the end portion of the upper core tube 2b and the height of the fixing member 5 can be aligned with each other, the waste of space is reduced. It can be stored and transported.

  FIG. 6 is another example of the master rope support according to the present invention. (a) is a front view, (b) is a right side view, and (c) is a cross-sectional view (enlarged view) taken along line AA.

  This master rope 1 is composed of a pillar main body, a master rope holding metal fitting 10 attached to the upper end of the pillar main body, and a fixing member 5 for fixing to a flange portion of a steel beam made of H-shaped steel.

  It differs from the master rope support shown in FIG. 1 only in that the cross section of the support main body is square. That is, the column main body is composed of a lower sheath tube 2a composed of a tapered tube having a square section with a narrower cross section upward, and an upper core tube 2b that can be inserted and fixed inside the sheath tube 2a. Thus, the upper core tube 2b is manufactured from a straight tube having a square cross section. Here, the lower sheath tube 2a is a taper having a square cross section by cutting a steel plate into a trapezoidal shape, folding the plate into three vertically, facing each other, and performing line welding W between both sides. It is formed into the shape of a tube (see FIG. 6 (c)). And the connection part 2c which consists of a straight pipe with a square cross section is provided in the upper end part of the sheath pipe 2a so that the lower end part of the core pipe 2b may be fitted and inserted in it.

  The side surface of the upper core tube 2b has a total of four holes including two lower holes 4a in the vicinity of the lower end and two upper holes 4b in the middle. It is installed in a state of being biased outward. That is, a lower pin 3a is installed inside each of the two lower holes 4a near the lower end, and an upper pin 3b is installed inside each of the middle two upper holes 4b. The spring steel 8 attached to the inside of 2b is urged outward so that the heads of the upper pin 3a and the lower pin 3b come out of the respective holes.

  The connecting portion 2c has two holes 4c, and the two lower pins 3a provided near the lower end of the side surface of the upper core tube 2b have two heads drilled in the connecting portion 2c. From the hole 4c. Since the two lower pins 3a are urged outward by spring steel, the lower pins 3a must be separated from the two holes 4c formed in the connecting portion 2c unless the head of the lower pins 3a is pressed by human power. There is no.

  In this way, the upper core tube 2b is pulled out to the maximum from the lower sheath tube 2a by taking out the head of the lower pin 3a of the upper core tube 2b from the two holes 4c drilled in the connecting portion 2c. Can be fixed in the state. Here, the pin itself serves as a stopper.

  The column body is erected and fixed on the flange portion of the steel beam with an inclination angle of 10 ° in the direction away from the steel beam toward the upper end of the column body. The pipe 2a is joined by welding in an inclined state with respect to the fixing member 5 by 10 °. The fixing member 5 has a vise structure and has a U-shaped curved portion when viewed from the side. A lower fixing plate 6 is provided on the lower surface of the U-shaped curved portion, and a mounting bolt 7 is provided on the upper surface. The fixing member 5 can be fixed to the flange portion of the steel beam by fitting the flange portion of the steel beam on the lower fixing plate 6 and tightening the mounting bolt 7 from above. Here, 10 ° is adopted as the inclination angle in the direction away from the steel beam toward the upper end of the column main body, but the inclination angle in the direction away from the steel beam toward the upper end of the column main body is 5 ° to 20 °. Can be selected as appropriate. Further, the lower sheath pipe 2a of the column main body may be joined to the U-shaped fixing member 5 by welding in an upright state without adopting an inclination angle.

  Furthermore, a handle 15 is attached to the side surface of the lower sheath tube 2a so that the main rope support 1 can be easily handled during transportation and storage. In addition, a width adjusting member 17 is attached to the side surface of the end portion of the upper core tube, and the height of the end portion of the upper core tube 2b is set in a state where a plurality of the master rope support columns 1 are placed sideways. And the height of the fixing member 5 can be made uniform.

  In the same manner as shown in FIG. 2, this master brace 1 is fitted with the flange portion 20 a of the steel beam 20 in the U-shaped curved portion of the fixing portion 5, and then the flange portion 20 a of the steel beam 20. By tightening the mounting bolt 7 on the upper part, the two master rope support columns 1 are erected on the flange portion 20a of the steel beam 20 and fixed. Then, the master rope 30 is bridged by connecting the master rope holding bracket 10 attached to the upper end of each master rope support 1.

  The operator 31 is in a state of walking along the master rope 30 after hooking the hook 33 provided at the tip of the safety belt 32 attached to the waist to the master rope 30 and locking (not shown). The operator 31 can walk on the flange 20 a of the steel beam 20 along the master rope 30.

  Similarly to the case shown in FIG. 3, when the operator 31 mistakenly steps off the steel beam 20 and falls, the impact load corresponding to the weight of the operator 31 is perpendicular to the parent rope 30. Acting on the master rope 30, a tensile force acts on the master rope 30, and a force for pulling the master rope holding fittings 10 attached to the upper end of the master rope support 1 is generated.

  However, the master rope column 1 is composed of a lower sheath tube 2a having a tapered tube and a lower core tube 2b inserted and fixed inside the sheath tube, and the lower sheath tube 2a. Since the stress concentration part with a small cross-sectional area is provided in the core tube part directly above the upper end of the steel pipe, when the operator falls from the steel beam, the main strut main body bends at this stress concentration part. The fall distance of the person can be short. Moreover, since the cross-sectional area of this stress concentration part is small, it becomes easy to bend, so that the amount of elastic deformation before the core tube part just above the upper end of the sheath tube is bent increases. Therefore, the impact load acting on the dropped operator can be reduced.

  And the repair of the bent main rope supporter in this way is only necessary to replace the bent upper core tube 2b.

  FIG. 7 is an example when the upper core tube of the master rope support shown in FIG. 6 is accommodated in the lower sheath tube. (a) is a front view and (b) is a right side view.

  From the state shown in FIG. 6, the upper core tube 2 b is pushed down from the hole 4 c formed in the connection portion 2 c while the heads of the two lower pins 3 a of the upper core tube 2 b are pressed by human power. The core tube 2a is pushed into the upper core tube 2b, and then the heads of the two upper pins 3b of the upper core tube 2b are taken out from the hole 4c formed in the connecting portion 2c, thereby the upper core tube is removed from the lower sheath tube 2a. 2b can be fixed in a state of being pulled out to the minimum. Again, since the two upper pins 3b are urged outward by the spring steel 8, unless the head of the upper pin 3b is pressed by human power, the two holes 4c drilled in the connecting portion 2c are used. Since the pin does not come off, the pin itself serves as a stopper.

  This master rope 1 also has a width adjusting member 17 attached to the side surface of the end of the upper core tube 2b, and a part of the upper core tube 2b is accommodated in the lower sheath tube 2a. In the state where a plurality of the master rope support columns 1 are placed sideways, the height of the end portion of the upper core tube 2b and the height of the fixing member 5 can be aligned, so that it is the same as shown in FIG. It is possible to reduce the waste of space and to store and transport a plurality of master rope support columns 1.

  According to the present invention, the master rope column main body is formed by reducing the weight of the master rope column main body and providing the stress concentration portion on the column main body without forming any concave and convex portions and concave portions on the side of the main rope column main body. Can be provided.

DESCRIPTION OF SYMBOLS 1 Master rope support 2a Sheath pipe 2b Core pipe 2c Connection part 3a Lower pin 3b Upper pin 4a Core pipe lower hole 4b Core pipe upper hole 4c Connection part hole 5 Fixing member 6 Lower fixing plate 7 Mounting bolt 8 Spring steel 10 Master rope holding bracket 15 Handle 17 Width adjusting member 20 Steel beam 20a Steel beam flange 30 Master rope 31 Worker 32 Safety belt 33 Hook W Welding

Claims (5)

  A main strut strut comprising a strut body, a master rope holding bracket attached to the upper end portion of the pillar main body, and a fixing member for fixing to the flange portion of the steel beam. A parent rope supporter comprising a lower sheath tube made of a tapered tube having a narrow width and an upper core tube that can be inserted and fixed inside the sheath tube.   The master rope support post according to claim 1, wherein a width adjusting member is attached to a side surface of an end portion of the upper core pipe.   3. The master rope support column according to claim 1 or 2, wherein the lower sheath tube is provided with an inclination angle in a direction away from the steel beam toward the upper end of the support column main body.   The master rope support according to any one of claims 1 to 3, wherein a cross-sectional shape of the lower sheath tube is a quadrangle.   The main rope support according to any one of claims 1 to 3, wherein a cross-sectional shape of the lower sheath tube is circular.

Images