Main rope attachment

Abstract

To provide a main rope attachment tool capable of preventing preferable absorption of a load transferred from a main rope from being obstructed.SOLUTION: A main rope attachment tool 10 includes: a base 11 which is installed on a roof; and a column 12 which is fixed on the base 11 and to which a main rope is connected. The base 11 includes a column fixing part 20, a base part 21, and two frame parts 22. Each of the frame parts 22 includes an outer frame part 31, and the frame connection part 32 connecting the outer frame part 31 and the base part 21. The frame connection frame part 32 includes: two end connection parts 33 connecting both ends of the outer frame part 31 and the base part 21 to each other; and a base connection part 34 sandwiched between the two end connection parts 33. The column fixing part 20 is arranged at a portion where the base part 21 and the base connection part 34 are connected to each other. Both ends part 21a of the base part 21 have lower rigidity than that of a portion where each of the base connection parts 34 and each of the outer frame parts 31 in each of the frame parts 22 are connected.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a main cable fixture.

Background Art

[0002] Conventionally, workers performing work at heights use lifelines for safety. The lifeline is used by hooking it to the main cable stretched across the high working area. When stretching the main cable across the high working area, for example, the main cable fixture described in Patent Document 1, more specifically, the main cable fixture having a base and a support column, is used. The base is a pedestal that is fixed and used on, for example, a roof or the like, which is the high working area. The support column has a connecting ring for connecting the main cable and is fixed to the base. The end portion of the support column on the side opposite to the side where the connecting ring is provided is fixed in a state of being inserted into a sleeve provided on the base. The sleeve on the base is fixed to the grooved steel material constituting the base via ribs. When the main cable fixture is fixed on a roof or the like and a load acts through the main cable, the load transmitted from the main cable is transmitted to the base in the order of the support column, the sleeve, and the ribs. The base to which the load is thus transmitted can absorb the load transmitted from the main cable by undergoing torsional deformation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the main cable fixture, if the load transmitted from the main cable concentrates on a specific location, suitable absorption of the load will be hindered. That is, when absorbing the load transmitted from the main cable, it is required to suppress the concentration of the load on a specific location.

Means for Solving the Problems

[0005] The following describes various forms of lifeline attachment devices that can solve the above problems. [Aspect 1] A lifeline attachment device configured to stretch a lifeline by connecting a lifeline to which a safety line is attached, comprising: a base installed in a workplace; and a support column fixed to the base and to which the lifeline is connected, wherein the base comprises: a base portion extending in one direction; two frame portions arranged on opposite sides of the base portion; and a support column fixing portion for fixing the support column, wherein the frame portion comprises: an outer frame portion extending in the direction in which the base portion extends; and a connecting frame portion connecting the outer frame portion and the base portion, wherein the connecting frame portion comprises: two end connecting portions connecting both ends of the outer frame portion and the base portion; and a base connecting portion sandwiched between the two end connecting portions, wherein the support column fixing portion is provided at the portion where the base portion and the base connecting portion are connected to each other, and both ends of the base portion have lower rigidity than the portion where the base connecting portion and the outer frame portion are connected.

[0006] According to the above configuration, when a load is applied to the lifeline attachment via the lifeline, the load transmitted from the lifeline is transmitted from the support column to the support column fixing part. The load transmitted to the support column fixing part is then transmitted from the support column fixing part to the base part and each base connection part connected to the support column fixing part. The load transmitted to the base part and each base connection part is then transmitted to each end connection part and each outer frame part, thereby transmitting to each frame part. In other words, the load transmitted from the lifeline is transmitted in the order of support column, support column fixing part, base part, and each base connection part, and then transmitted to each end connection part and each outer frame part, and finally to the entire base. In addition, the load transmitted from the lifeline is transmitted to the work area where the lifeline attachment part is installed via each outer frame part. This makes it possible to suppress the concentration of the load transmitted from the lifeline in a specific place.Therefore, suitable deformation can be made to both ends of the base part, which have lower rigidity than the parts where each base connection part is connected to each outer frame part, among the base part and each base connection part connected to the support column fixing part. This is effective in preventing interference with the proper absorption of load transmitted from the main rope.

[0007] [Aspect 2] The base portion, the outer frame portion, and the base connection portion are channel-shaped steel members having flange portions extending in the direction in which the support column extends, the end connection portion is an angle-shaped steel member forming a V-shape extending in the direction in which the support column extends and in a direction approaching each other, reinforcing plates having surfaces intersecting the direction in which the base portion extends are joined to both ends of the base portion by welding, the frame end of the base connection portion opposite to the base portion is joined to the flange side of the outer frame portion by welding from the base portion side, and the area in which the reinforcing plate is welded is smaller than the area in which the frame end is welded to the flange side of the outer frame portion, as described in [Aspect 1].

[0008] According to the above configuration, a lower rigidity configuration can be suitably achieved for the base portion than the portion where the base connection portion and the outer frame portion are connected. [Aspect 3] The main rope attachment device according to [Aspect 2], wherein the support column fixing portion is cylindrical having an opening for inserting the support column, and the base portion of the support column fixing portion opposite to the opening includes a web joint portion that is welded to the web of the base portion and a flange joint portion that is welded to the tip of the respective flange portions of the base portion and the base connection portion.

[0009] According to the above configuration, the support post fixing part can be joined to the base part and base connection part via the web joint part and flange joint part. For example, if the load transmitted from the lifeline is large, the support post fixing part can absorb a portion of the load transmitted from the lifeline by, for example, by breaking a part of the flange joint part. This prevents the load transmitted from the lifeline from concentrating on the support post. Therefore, when a load is applied to the lifeline attachment device through the lifeline, it is possible to prevent the support post from breaking or other such incidents from occurring.

[0010] [Aspect 4] A lifeline attachment device according to any one of [Aspect 1] to [Aspect 3], wherein the base portion has a weight-reducing hole that penetrates the base portion.

[0011] According to the above configuration, a lower rigidity configuration for the base section than for each base connection section can be suitably achieved. Therefore, deformation of both ends of the base section can also be accompanied by deformation of the base section itself. This is effective in suitably absorbing a portion of the load transmitted to the base section and each base connection section, respectively.

[0012] [Aspect 5] The main rope attachment device according to [Aspect 4], wherein the base portion has fixing holes for fixing the base to the work area, and the fixing holes in the base portion also serve as weight-reducing holes.

[0013] According to the above configuration, when suitably achieving a lower rigidity configuration for the base portion than for the base connection portion, the process of forming weight-reducing holes, i.e., fixing holes, can be reduced. [Aspect 6] The support column has a plurality of connecting rings for connecting the main rope, the plurality of connecting rings protrude radially outward from the support column at the end of the support column opposite to the support column fixing portion, having connecting openings in the circumferential direction of the support column, and the phases of the plurality of connecting rings are offset by equal angles from each other in the circumferential direction of the support column, as described in any one of [Aspect 1] to [Aspect 5].

[0014] According to the above configuration, the main rope can be connected from the circumferential direction regardless of the orientation in which the base is positioned. This is effective in improving the convenience of positioning the base, i.e., the main rope attachment device.

[0015] [Aspect 7] The support post fixing portion is cylindrical with an opening for inserting the support post, and has a plurality of fixing portion connecting rings for connecting the main rope, the plurality of fixing portion connecting rings protruding radially outward from the support post fixing portion such that they have connecting openings in the circumferential direction of the support post fixing portion between the opening and the base portion opposite to the opening, and the phases of the plurality of fixing portion connecting rings are offset by equal angles from each other in the circumferential direction of the support post fixing portion, as described in any one of [Aspect 1] to [Aspect 6].

[0016] According to the above configuration, even at a position closer to the pedestal, that is, at a lower position, the main rope can be connected. This is effective for improving the convenience when stretching the main rope over the workplace.

Advantages of the Invention

[0017] According to the present invention, it is possible to suppress the prevention of suitable absorption of the load transmitted from the main rope.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view of the main rope fixture according to the embodiment. [Figure 2] It is a perspective view of the pedestal included in the main rope fixture of FIG. 1 as viewed from above. [Figure 3] It is a plan view of the pedestal of FIG. 2 as viewed from above. [Figure 4] It is a cross-sectional view taken along line 4-4 of FIG. 3. [Figure 5] It is a cross-sectional view taken along line 5-5 of FIG. 3. [Figure 6] It is a plan view of the pedestal of FIG. 2 as viewed from the side. [Figure 7] It is a cross-sectional view taken along line 7-7 of FIG. 3. [Figure 8] It is a view for explaining another usage state of the main rope fixture of FIG. 1.

Mode for Carrying Out the Invention

[0019] Hereinafter, a main rope fixture according to an embodiment will be described with reference to the drawings. As shown in Figure 1, the lifeline attachment device 10 is used to prevent workers from falling from elevated work areas, such as on a roof Y. Roof Y includes corrugated metal roofs, as well as large wave roofs, slate roofs, and small wave roofs. The lifeline attachment device 10 stretches the lifeline R across the elevated work area by connecting the lifeline R. The lifeline R includes ropes made of natural or synthetic fibers, as well as wire ropes made of metal wire. The safety line L used by workers is attached to the lifeline R stretched across the elevated work area. In the following description, directions such as "up" and "down" are defined relative to the direction of gravity.

[0020] <Main rope attachment device> The lifeline attachment device 10 comprises a base 11 and a support column 12. The base 11 is installed in the workshop. The base 11 has a support column fixing part 20 for fixing the support column 12. The shape of the support column fixing part 20 is cylindrical with a circular opening 20a for inserting the support column 12. The opening 20a is provided at the upper end of the support column fixing part 20, which is the side that is spaced away from the roof Y. For example, the support column fixing part 20 is a sheath tube. The support column 12 has its first end 12a inserted into the support column fixing part 20 from the side of the opening 20a. In other words, the support column 12 extends upward from the base 11 with its first end 12a on the lower side and its second end 12b on the opposite side of the first end on the upper side. The support column 12 is fixed by a pin or the like while inserted into the support column fixing part 20. The support post 12 has connecting rings 12c for connecting the main rope R. There are four connecting rings 12c. Each connecting ring 12c is located at the second end 12b of the support post 12. Each connecting ring 12c protrudes radially outward from the support post 12 so that it has a connecting opening in the circumferential direction of the support post 12. The phases of each connecting ring 12c are offset by 90 degrees, which are equal angles to each other in the circumferential direction of the support post 12. When viewed from above, the connecting rings 12c are arranged in a cross shape.

[0021] <Base> As shown in Figures 2 and 3, the base 11 has a support column fixing part 20, a base part 21, and two frame parts 22.

[0022] The base portion 21 and each frame portion 22 are connected to each other to form a grid-like frame 16. The base portion 21 extends in one direction (horizontal direction) perpendicular to the vertical direction. Each frame portion 22 is arranged on opposite sides of the base portion 21. When viewed from above, each frame portion 22 is point-symmetric with respect to the support column fixing portion 20. Each frame portion 22 has an outer frame portion 31 and a connecting frame portion 32. The outer frame portion 31 extends in the direction in which the base portion 21 extends. The total length of the outer frame portion 31 is the same as the total length of the base portion 21. The connecting frame portion 32 has two end connecting portions 33 and a base connecting portion 34.

[0023] Each end connector 33 and base connector 34 extends in a direction perpendicular to the direction in which the base 21 extends. The total length of each end connector 33 and base connector 34 is less than that of the base 21, i.e., the outer frame 31.

[0024] Each end connection portion 33 connects the ends of the base portion 21 and the outer frame portion 31. Each end connection portion 33 connects the opposing flange sides of both ends 21a of the base portion 21 and both ends 31a of the outer frame portion 31.

[0025] The base connection portion 34 is sandwiched between each end connection portion 33. The base connection portion 34 is positioned such that the distance between each end connection portion 33, i.e., the distance from each end connection portion 33, is the same. In other words, the base connection portion 34 connects the longitudinal centers of the base portion 21 and the outer frame portion 31. The base connection portion 34 connects the longitudinal center portion 21b of the base portion 21 and the longitudinal center portion 31b of the outer frame portion 31, between their opposing flange sides.

[0026] In the base section 21, a support column fixing section 20 is fixed to the central part 17 of the frame 16, which is the point where the base section 21 and the base connection sections 34 of each frame section 22 intersect. The support column fixing section 20 is fixed to the frame 16 via a base section 20b on the opposite side of its opening 20a. Between the opening 20a and the base section 20b of the support column fixing section 20, there are two pin holes 20c, two connecting rings 20d, and a welded plate 20e. Each pin hole 20c is used when inserting pins or the like to fix the support column 12. Each pin hole 20c is a through hole that penetrates the peripheral wall of the support column fixing section 20. Each connecting ring 20d is used when connecting the main rope R. Each connecting ring 20d protrudes radially outward from the support column fixing section 20 so as to have a connecting opening in the circumferential direction of the support column fixing section 20. The phases of each connecting ring 20d are offset by 180 degrees, which is an equal angle to each other in the circumferential direction of the support column fixing part 20. When viewed from above, each connecting ring 20d is arranged in an I-shape. The welding plate 20e is used to fix the support column fixing part 20 to the frame 16. When viewed from above, the welding plate 20e protrudes radially outward from the support column fixing part 20 so that it has a rectangular shape. In this embodiment, the connecting ring 20d is an example of a connecting ring for a fixing part.

[0027] <About the frame> As shown in Figures 2 and 3, the frame 16 is constructed by joining together, for example, a base portion 21, two outer frame portions 31, four end connection portions 33, and two base connection portions 34, each made of steel bars, by welding, such as fusion welding. Note that, in addition to fusion welding, other welding methods such as pressure welding or brazing may also be used.

[0028] More specifically, the base portion 21 is a channel steel member having a groove that opens upward. The base portion 21 has two flange portions 41 extending upward and a web 42 connecting the lower ends 41a of each flange portion 41. The upper tip portions 41b of each flange portion 41 are bent so that their tips face each other. The web 42 is provided with fixing holes 43 that penetrate the web 42 in the thickness direction. The fixing holes 43 include circular holes 43a and oval-shaped elongated holes 43b when viewed from above. The oval shape is, for example, a rounded rectangle formed by connecting two semicircles with two line segments. One elongated hole 43b is located at each end of the web 42. Between the two elongated holes 43b, a plurality of circular holes 43a are provided at equal intervals along the longitudinal direction of the web 42. In this case, the fixing holes 43 are located along the longitudinal direction at the center of the short side of the frame 16, i.e., the base 11. The fixing holes 43 are used to fix the base 11 to the workshop. In addition to fixing the base 11 to the workshop, the fixing holes 43 are also used to reduce the rigidity of the web 42. In other words, the fixing holes 43 also serve as weight-reducing holes to reduce the rigidity of the web 42.

[0029] Each outer frame section 31, like the base section 21, is a channel-shaped steel material having a groove that opens upward. Each outer frame section 31 has two flange sections 51 extending upward and a web 52 connecting the lower ends 51a of each flange section 51. The upper tip 51b of each flange section 51 is bent so that its tip faces the other. The web 52 is provided with fixing holes 53 that penetrate the web 52 in the thickness direction. The fixing holes 53 are oval-shaped when viewed from above. One fixing hole 53 is located at each end of the web 52. In this case, the fixing holes 53 are located at the four corners of the frame 16, i.e., the base 11. The fixing holes 53 are used when fixing the base 11 to the workshop.

[0030] Each end connection portion 33 is an L-shaped steel member (L-shaped steel member) that extends upward and toward each other. Each end connection portion 33 has a wall portion 61 that extends upward and an extended portion 62 that extends so that the tips of the upper end portion 61a of the wall portion 61 face each other.

[0031] Each base connection portion 34, like the base portion 21, is a channel-shaped steel material having a groove that opens upward. Each base connection portion 34 has two flange portions 71 extending upward and a web 72 connecting the lower ends 71a of each flange portion 71. The upper tip portions 71b of each flange portion 71 are bent so that their tips face each other.

[0032] <Regarding the joining of the frame parts> As shown in Figures 3 and 4, in each frame section 22, the outer frame section 31 and each connecting frame section 32 (each end connecting section 33 and base connecting section 34) are joined by welding.

[0033] More specifically, each end connection portion 33 is welded to the flange side surface of the outer frame portion 31, with the tip of the first end 33a in the longitudinal direction facing the outer surface of one flange portion 51 of the outer frame portion 31. The entire tip of the first end 33a of each end connection portion 33 is welded. In this case, each welded joint 81 is formed at both ends 31a of the outer frame portion 31 as an L-shaped portion, which is the cross-sectional shape of the wall portion 61 and the extended portion 62.

[0034] The base connection portion 34 is welded to the flange side of the outer frame portion 31, with the tip of the first end 34a in the longitudinal direction facing the outer surface of one flange portion 51 of the outer frame portion 31. The entire tip of the first end 34a of the base connection portion 34 is welded. In this case, the welded joint 82 is formed in the central portion 31b of the outer frame portion 31 as a U-shaped portion, which is the cross-sectional shape of each flange portion 71 and web 72. In this embodiment, the first end 34a of each base connection portion 34 is an example of a frame end.

[0035] <Regarding the connection between the base and the frame> As shown in Figures 3 and 5, in the frame 16, the base portion 21 and each frame portion 22 are joined by welding. The base portion 21 and each frame portion 22 are welded to each other via the end connection portions 33 and base connection portions 34 of each frame portion 22.

[0036] More specifically, each end connection portion 33 is welded to the flange side surface of the base portion 21, with the tip of the second end 33b opposite the first end 33a facing the outer surface of one flange portion 41 of the base portion 21. The entire tip of the second end 33b in each end connection portion 33 is welded. In this case, each welded joint 83 is formed at both ends 21a of the base portion 21 as an L-shaped portion, which is the cross-sectional shape of the wall portion 61 and the extended portion 62.

[0037] The base connection portion 34 is welded to the flange side surface of the base portion 21, with the tip of the second end 34b opposite the first end 34a facing the outer surface of one flange portion 41 of the base portion 21. The entire tip of the second end 34b of the base connection portion 34 is welded. In this case, the welded joint 84 is formed in the central portion 21b of the base portion 21 as a U-shaped portion, which is the cross-sectional shape of each flange portion 71 and web 72.

[0038] <Regarding the joining of reinforcing plates> As shown in Figures 2 and 3, reinforcing plates 18 are welded to the frame 16 for reinforcement. The reinforcing plates 18 are thin plates, and their thickness is approximately the same as the thickness of other parts such as the base portion 21 and the outer frame portion 31. The reinforcing plates 18 include two base reinforcing plates 44 provided in the grooves of the base portion 21 and four frame reinforcing plates 54 provided in the grooves of each outer frame portion 31.

[0039] As shown in Figures 3 and 6, each base reinforcing plate 44 is welded to the groove of the base portion 21 with its surface perpendicular to the direction in which the base portion 21 extends. In other words, each base reinforcing plate 44 is welded to the groove of the base portion 21 with its peripheral edge 44a facing the inner surfaces of each flange portion 41 and the web 42 of the base portion 21. A portion of the peripheral edge 44a of each base reinforcing plate 44 is welded. In this case, each welded joint 85 is formed at both ends 21a of the base portion 21 as a discontinuous shape, such as a portion of the inner surface of each flange portion 41 and a portion of the inner surface of the web 42, excluding the bent portion of the base portion 21. The bent portion of the base portion 21 is the bent tip of each flange portion 41 and the connecting portion between each flange portion 41 and the web 42.

[0040] Each welded joint 85 is formed with a smaller welded area than each welded joint 82. As a result, each welded joint 85, where each base reinforcing plate 44 is welded to the groove in the base portion 21, is less rigid than each welded joint 82, where each base connection portion 34 is welded to the flange side of each outer frame portion 31. In other words, both ends 21a of the base portion 21 are less rigid than the parts where each base connection portion 34 and each outer frame portion 31 are connected.

[0041] As shown in Figures 3, 6, and 7, each frame reinforcing plate 54 is welded to the groove of the outer frame portion 31 with its surface perpendicular to the direction in which the outer frame portion 31 extends. In other words, each frame reinforcing plate 54 is welded to the groove of the outer frame portion 31 with its peripheral edge 54a facing the inner surface of each flange portion 51 and web 52 of the outer frame portion 31. A portion of the peripheral edge 54a of each frame reinforcing plate 54 is welded. In this case, each welded joint 86 is formed at both ends 31a and the central portion 31b of the outer frame portion 31 as a discontinuous shape, such as a portion of the inner surface of each flange portion 51 and a portion of the inner surface of the web 52, excluding the bent portion of the outer frame portion 31. The bent portion of the outer frame portion 31 is the bent tip of each flange portion 51 and the connecting portion between each flange portion 51 and the web 52.

[0042] Each welded joint 86 is formed on the extension of each welded joint 82 in the direction in which each base connection 34 extends. As a result, the rigidity of each welded joint 82, where each base connection 34 is welded to the flange side surface of each outer frame 31, is reinforced by each frame reinforcing plate 54 and each welded joint 86. In this case, each welded joint 85, where each base reinforcing plate 44 is welded to the groove of the base 21, is less rigid than each welded joint 82, where each base connection 34 is welded to the flange side surface of each outer frame 31. In other words, both ends 21a of the base 21 are less rigid than the parts where each base connection 34 and each outer frame 31 are connected.

[0043] <Regarding the connection of the support column fixing part> As shown in Figure 7, in the base 11, the frame 16 and the support column fixing part 20 are joined by welding. The frame 16 and the support column fixing part 20 are welded to each other via the base part 21 and the base connection part 34.

[0044] More specifically, the support fixing portion 20 is welded to a groove in the base portion 21 with the tip of the base portion 20b facing the upper surface of the web 42 of the base portion 21. The entire tip of the base portion 20b is welded. In this case, the welded joint portion 87 is formed in the central portion 21b of the base portion 21, i.e., the central part 17 of the frame 16, as a circular portion which is the cross-sectional shape of the base portion 20b. In this embodiment, the welded joint portion 87 is an example of a web joint portion.

[0045] Furthermore, the support column fixing portion 20 is welded to the base portion 21 and each base connection portion 34 with the welded plate 20e of the base portion 20b facing the tip portions 41b of each flange portion 41 of the base portion 21 and the tip portions 71b of each flange portion 71 of each base connection portion 34 from above. A portion of the lower surface of the welded plate 20e is welded. In this case, the welded joint portion 88 is formed in the central portion 21b of the base portion 21 and the second end 34b of each base connection portion 34, i.e., the central portion 17 of the frame 16, as a cross-shaped portion facing the tip of each flange portion 41 and each flange portion 71. In this embodiment, the welded joint portion 88 is an example of a flange joint portion.

[0046] <Regarding the usage of the lifeline attachment device> Figure 1 shows the usage of the lifeline attachment device 10 on a corrugated metal roof Y. For example, roof Y is fixed to a steel frame base via a tight frame fixed to the steel frame base. Roof Y is fixed to the tight frame with nuts, etc. In this case, the base 11 is positioned so that the longitudinal direction of the base portion 21 is perpendicular to the direction in which the ridges Ya of the corrugated metal roof extend. The base 11 is fixed to roof Y, i.e., the tight frame, with nuts, etc., via fixing holes 43 that are located in the range that contacts the ridges Ya, among the fixing holes 43 that also serve as weight-reducing holes provided in the base portion 21. For example, in Figure 1, the fixing holes 43 used for fixing to roof Y are three round holes 43a and one elongated hole 43b. This completes the installation of the lifeline attachment device 10.

[0047] Figure 8 shows the use of the lifeline attachment device 10 on a corrugated roof Y. In this case, the base 11 is positioned so that the longitudinal direction of the base portion 21 coincides with the direction in which the peaks Yb of the corrugated roof extend. The base 11 is positioned so that the longitudinal direction of each outer frame portion 31 is perpendicular to the steel frame base Yc that extends along a direction perpendicular to the direction in which the peaks Yb extend on the underside of the peaks Yb of the corrugated roof. The base 11 is fixed to the roof Y with screws or the like through fixing holes 53 provided in each outer frame portion 31 that are located in the range that overlaps with the steel frame base Yc in the vertical direction. For example, in Figure 8, the fixing holes 53 used for fixing to the roof Y are all four corners. This completes the installation of the lifeline attachment device 10.

[0048] <Operation of this embodiment> As shown in Figure 1, once the lifeline attachment device 10 is installed, the lifeline R is stretched over the roof Y by connecting the lifeline R to the connecting rings 12c of the support column 12. Figure 1 shows the case where the lifeline R is connected to two connecting rings 12c provided in the direction in which the base portion 21 extends. A safety line L used by workers is attached to the lifeline R stretched over the roof Y. The lifeline R may also be connected to four or three connecting rings 12c, or to two adjacent connecting rings 12c in the circumferential direction of the support column 12.

[0049] For example, when a load is applied to the lifeline attachment 10 through the lifeline R, i.e., the safety rope L, the load transmitted from the lifeline R is transmitted from the support column 12 to the support column fixing part 20. The load transmitted to the support column fixing part 20 is then transmitted from the support column fixing part 20 to the base part 21 and each base connection part 34 connected to the support column fixing part 20. The load transmitted to the base part 21 and each base connection part 34 is then transmitted to each end connection part 33 and each outer frame part 31, thereby being transmitted to each frame part 22. In other words, the load transmitted from the lifeline R is transmitted in the order of support column 12, support column fixing part 20, base part 21, and each base connection part 34, and then transmitted to the entire base 11 in the order of each end connection part 33 and each outer frame part 31. In addition, the load transmitted from the lifeline R is transmitted to the peak Ya of the roof Y via each outer frame part 31. This prevents the load transmitted from the main rope R from concentrating on a specific point.

[0050] In this way, as the load transmitted from the main rope R is transmitted to the entire base 11, suitable deformation can be brought about at both ends 21a of the base portion 21, which is connected to the support fixing portion 20 and each base connection portion 34.

[0051] For example, in the usage state shown in Figure 1, the base 11 deforms around the base portion 21 which is installed and fixed to the roof Y. In this case, the base portion 21 deforms so that each flange portion 41 moves closer to each other, as each base reinforcing plate 44 bends, especially at both ends 21a which have low rigidity. As a result, the frame 16 deforms so that the entire frame portion 22 on the side opposite to where the load is transmitted from the main rope R moves away from the roof Y around the base portion 21. On the other hand, each frame portion 22 can maintain its original state. This is also true in the usage state shown in Figure 8. In other words, the base 11 deforms around the base portion 21 which is not installed and fixed to the roof Y. In this case, the base portion 21 deforms so that each flange portion 41 moves away from each other, as each base reinforcing plate 44 extends, especially at both ends 21a which have low rigidity. As a result, the frame 16 deforms so that the base portion 21 moves away from the roof Y. On the other hand, each frame portion 22 can maintain its original state.

[0052] Furthermore, any remaining load that cannot be absorbed by deformation around the base 21 is distributed and transmitted to various parts of the base 11. For example, the remaining load is absorbed in the frame section 22 on the side to which the load is transmitted from the main rope R by deformation such as bending of each end connection part 33 or the base connection part 34 itself. Also, the remaining load is absorbed in the part of the roof Y where the frame section 22 on the side to which the load is transmitted from the main rope R is installed by deformation such as bending of the mountain Ya itself. In addition, the remaining load is absorbed in the support column fixing part 20 by deformation such as a part of the welded joint 88 breaking. In this case, the welded joint 87 can maintain its original state. In other words, the main rope attachment device 10 can absorb the load transmitted from the main rope R without separating or breaking the base 11.

[0053] As described above, the lifeline attachment device 10 can prevent the load transmitted from the lifeline R from concentrating at a specific point. <Effects of the Embodiment> (1-1) The lifeline attachment device 10 prevents the load transmitted from the lifeline R from concentrating at specific points, thereby allowing both ends 21a of the base portion 21 to undergo appropriate deformation. This is effective in preventing interference with the appropriate absorption of the load transmitted from the lifeline R.

[0054] (1-2) Any remaining load that cannot be absorbed by deformation around the base section 21 is transmitted to the peak Ya of the roof Y via the outer frame section 31 at the frame section 22 on the side to which the load is transmitted from the main rope R. As a result, the peak Ya can absorb the remaining load by deforming, such as bending. This is effective in suitably absorbing a portion of the load transmitted from the main rope R.

[0055] (1-3) Each welded joint 85 is formed with a smaller welding area than each welded joint 82. This makes it possible to suitably achieve a configuration with lower rigidity at both ends 21a of the base portion 21 than at each welded joint 82 to which each base connection portion 34 and each outer frame portion 31 are connected.

[0056] (1-4) The base 20b of the support post fixing part 20 is joined to the frame 16 via welded joints 87 and 88. For example, if the load transmitted from the lifeline R is large, the support post fixing part 20 can absorb a portion of the load transmitted from the lifeline R by breaking a part of the welded joint 88. This prevents the load transmitted from the lifeline R from concentrating on the support post 12 (especially the first end 12a on the side fixed to the support post fixing part 20). Therefore, when a load is applied to the lifeline attachment 10 through the lifeline R, it is possible to prevent the support post 12 from breaking or other such incidents.

[0057] (1-5) The base portion 21 has fixing holes 43 that penetrate the web 42. This allows for a configuration in which the web 42 of the base portion 21 has lower rigidity than each base connection portion 34. Therefore, deformation of both ends 21a of the base portion 21 can also be accompanied by deformation of the base portion 21 itself. This is effective in absorbing a portion of the load transmitted to the base portion 21 and each base connection portion 34, respectively.

[0058] (1-6) In the base portion 21, the fixing holes 43 also serve as weight-reducing holes. This allows for a lower rigidity configuration of the base portion 21 than that of each base connection portion 34, and reduces the process of forming the weight-reducing holes, i.e., the fixing holes 43.

[0059] (1-7) The support post 12 has four connecting rings 12c arranged in a cross shape when viewed from above. This allows the main rope R to be connected from all four sides, regardless of the orientation in which the base 11 is positioned. This is effective in improving the convenience of positioning the base 11, i.e., the main rope attachment device 10.

[0060] (1-8) The support post fixing section 20 has two connecting rings 20d arranged in an I-shape when viewed from above. This allows the main rope R to be connected even at a position closer to the base 11, i.e., at a lower position. This is effective in improving the convenience when stretching the main rope R over the roof Y.

[0061] <Other Embodiments> The above embodiments may be modified as follows. Furthermore, the following other embodiments can be combined with each other to the extent that they do not conflict with the technical standards.

[0062] The base portion 21 may have weight-reducing holes in addition to the fixing holes 43. In other words, the fixing holes 43 do not have to double as weight-reducing holes. In this case, the shape of the weight-reducing holes may be changed as appropriate, provided they are through holes.

[0063] The number of fixing holes 43 in the base portion 21 may be changed as appropriate. For example, the fixing holes 43 may consist only of round holes 43a, or only of elongated holes 43b. Alternatively, one of the elongated holes 43b may be changed to a round hole 43a. The number of round holes 43a may also be changed as appropriate, for example, to one. The same applies to the number and shape of the fixing holes 53 in each outer frame portion 31. For example, the fixing holes 53 may be perfectly round holes, or a mixture of oval-shaped elongated holes and round holes may be used.

[0064] The fixing holes 43 may be provided in each base connection portion 34 instead of in the base portion 21. Each base connection portion 34 may have fixing holes used to secure the base 11 to the workspace. In this case, the web 72 of each base connection portion 34 may have multiple fixing holes that penetrate the web 72 in the thickness direction.

[0065] The shape of the support column fixing part 20 may be changed as appropriate. For example, the shape of the support column fixing part 20 may be a rectangular tube, or the opening 20a may be square. If the opening 20a is square, the first end 12a of the support column 12 may be a square prism.

[0066] The support column fixing portion 20 may be joined to the frame 16 via only one of the welded joints 87 and 88. Alternatively, the support column fixing portion 20 may be joined to only one of the base portion 21 and each base connection portion 34. Furthermore, the welded joints 87 and 88 can also be realized as interconnected joints.

[0067] • The connection of the support column fixing part 20 to the frame 16 may be made by a method other than welding, as long as sufficient joint strength can be ensured. The support post fixing section 20 may have each connecting ring 20d removed. In other words, the support post fixing section 20 does not need to be configured to allow the main rope R to be connected.

[0068] • In the support column fixing section 20, the number of connecting rings 20d may be changed as appropriate, as long as there is one or more. For example, if there are three or more, the phases of the connecting rings 20d should be offset by equal angles from each other in the circumferential direction of the support column fixing section 20. In this case, the number of connecting rings 20d may be set to four so that the number of connecting rings 12c and the number of connecting rings 20d are equal.

[0069] In the support column fixing section 20, the phases of the four connecting rings 20d are not limited to equal angles, but may be offset by different angles from each other. This also applies when the number of connecting rings 20d is three or more.

[0070] The support column fixing portion 20 may be modified by removing the weld plate 20e. In other words, the welded joint 88 may be directly welded to the outer surface of the support column fixing portion 20. The type of steel bar used for the base portion 21, each outer frame portion 31, each end connection portion 33, and each base connection portion 34 that constitute the frame 16 may be changed as appropriate. For example, the base portion 21, each outer frame portion 31, and each base connection portion 34 may be channel-shaped steel bars that open downwards, or H-shaped steel bars may be used. In addition, each end connection portion 33 may be channel-shaped steel bars that open downwards or upwards, or steel bars may be used.

[0071] The welding area of ​​each welded joint 85 can also be changed if its welding area is smaller than the welding area of ​​each welded joint 82. Each welded joint 86 may be removed. Even in this case, each welded joint 85 can achieve the same effects as in the above embodiment, provided that its welding range is smaller than that of each welded joint 82.

[0072] The thickness of each base reinforcement plate 44 may be smaller than the thickness of other parts such as the base portion 21 and the outer frame portion 31. This allows for a suitable configuration in which each welded joint 85 has lower rigidity than each welded joint 82, even if the welding range of each welded joint 85 is the same as that of each welded joint 82.

[0073] Each base reinforcing plate 44, i.e., each welded joint 85, may be removed. Even in this case, the effects similar to those of the above embodiment can be achieved by making each welded joint 85 less rigid than each welded joint 82.

[0074] Each base reinforcing plate 44 should be welded to the groove of the base portion 21 with its surface intersecting the direction in which the base portion 21 extends. The base portion 21 can be reinforced in any of the other embodiments described herein.

[0075] • In the support column 12, the number of connecting rings 12c may be changed as appropriate, as long as there is one or more. For example, if there are two, three, five or more, the phases of the connecting rings 12c should be offset from each other by equal angles in the circumferential direction of the support column 12.

[0076] In the support column 12, the phases of the two connecting rings 12c are not limited to equal angles, but may be offset by different angles. This also applies when the number of connecting rings 12c is two, three, five or more.

[0077] In the main rope attachment device 10, the method for installing and fixing it on the roof Y may be to attach a fixing bracket to the lower side of the frame 16 so that the fixing bracket grips the peaks Ya and Yb of the roof Y. [Explanation of Symbols]

[0078] L...Lifeline R…Original rope Y (Ya, Yb)... roof (mountain) 10…Main rope attachment device 11…Pedestal 12…post 16...Frame 17…Center 20...Strut fixing part 20a…Aperture 20b…Base 21...Base section 21a...end 21b…Central part 22... Frame part 31…Outer frame section 31a...end 31b…Central part 32…Connecting frame section 33…End connection section 34...Base connection part 41…Flange section 41b...Tip 42…Web 43…Fixing hole 44…Base reinforcement plate 71…Flange section 71b...Tip 72…Web 82, 85, 87, 88... Welded joints

Claims

1. A lifeline attachment device configured to stretch a lifeline by connecting it to a lifeline to which a safety line is attached, A base to be installed in the workshop, It includes a support column that is fixed to the base and to which the main rope is connected, The base includes a support column fixing portion for fixing the support column, a base portion extending in one direction, and two frame portions arranged on opposite sides of the base portion. The frame portion includes an outer frame portion extending in the direction in which the base portion extends, and a connecting frame portion connecting the outer frame portion and the base portion. The connecting frame portion includes two end connecting portions that connect the outer frame portion and the base portion to each other, and a base connecting portion sandwiched between the two end connecting portions. The support column fixing portion is provided at the part where the base portion and the base connecting portion are connected to each other. The main rope attachment device wherein both ends of the base portion have lower rigidity than the portion of the frame portion where the base connection portion and the outer frame portion are connected.

2. The base portion, the outer frame portion, and the base connection portion are channel-shaped steel materials having flange portions that extend in the direction in which the support column extends. The end connection portion is an angle steel material that forms a V-shape, extending in the direction in which the support columns extend and in the direction in which they approach each other. Reinforcing plates having surfaces that intersect the direction in which the base portion extends are joined to both ends of the base portion by welding. The frame end of the base connection portion opposite to the base portion is joined to the flange side of the outer frame portion by welding from the base portion side. The lifeline attachment according to claim 1, wherein the area in which the reinforcing plate is welded is smaller than the area in which the frame end is welded to the flange side surface of the outer frame portion.

3. The support column fixing portion is cylindrical in shape and has an opening for inserting the support column. The lifeline attachment device according to claim 2, wherein the base portion of the support fixing portion opposite to the opening includes a web joint portion that is welded to the web portion of the base portion and a flange joint portion that is welded to the tip portions of the respective flange portions of the base portion and the base connection portion.

4. The main rope attachment device according to any one of claims 1 to 3, wherein the base portion has a weight-reducing hole that penetrates the base portion.

5. Of the base portion and the base connection portion, the base portion has fixing holes for fixing the base to the workspace. The main rope attachment device according to claim 4, wherein the fixing hole in the base portion also serves as the weight-reducing hole.

6. The support post has a plurality of connecting rings for connecting the main rope, The plurality of connecting rings protrude radially outward from the support column at the end of the support column opposite to the support column fixing portion, having connecting openings in the circumferential direction of the support column. The main rope attachment device according to any one of claims 1 to 3, wherein the phases of the plurality of connecting rings are offset by equal angles from each other in the circumferential direction of the support column.

7. The support post fixing portion is cylindrical with an opening for inserting the support post, and has a plurality of fixing portion connecting rings for connecting the main rope. The plurality of connecting rings for fixing parts protrude radially outward from the support column fixing part, having connecting openings in the circumferential direction of the support column fixing part between the base opposite to the opening and the opening. The main rope attachment device according to any one of claims 1 to 3, wherein the phases of the plurality of connecting rings for fixing parts are offset by equal angles from each other in the circumferential direction of the support fixing part.

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