JP2014066029A - Universal connector for balustrade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a universal connector for a balustrade which is capable of connecting two balustrade members at any angle in a three-dimensional manner without twisting them around an axis of the members.SOLUTION: A connection member 5 includes a concave circumferential surface part 51 resulting from rotating a longitudinal semicircular arc around a vertical axis 91. The concave circumferential surface part 51 is bisected into a concave circumferential surface upper half part 511 and a concave circumferential surface lower half part 512 by a horizontal surface 93 passing through a virtual center point 92 of the longitudinal semicircular arc, where the concave circumferential surface upper half part and the concave circumferential surface lower half part are connected with each other via a pivot member 9 so as to be able to rotate in a horizontal direction. A movable member 4 includes a convex part 42 in a hemispherical shell shape along the concave circumferential surface part 51, and a guide hole 45 in a slot shape is formed in the convex part 42. One movable member 4 is connected to the concave circumferential surface upper half part 511 while inserting an upper-side shaft member 7 through the guide hole 45, whereas another movable member 4 is connected to the concave circumferential surface lower half part 512 while inserting a lower-side shaft member 7 through the guide hole 45, thereby being rotatable independently in a vertical direction.

Description

  The present invention relates to a universal handrail connector that connects rod-shaped or tubular handrail members with variable angles.

  For example, when installing a handrail along a bent portion of a wall surface such as a staircase, it is necessary to connect linear handrail members while changing the direction at the bent portion. For example, Patent Literatures 1 to 3 disclose a handrail universal connecting portion used for such a portion.

  The basic structure of the handrail universal connector disclosed in these documents is a connecting member provided with a hemispherical concave surface portion on both sides, and a hemispherical shell-shaped convex surface portion fitted into the concave surface portion at one end. A guide hole is formed in the convex portion of each movable member, and the shaft member inserted through the guide hole is coupled near the center of the concave portion of the connecting member. Thus, the movable member and the connecting member are configured such that the connecting angle between the movable member and the connecting member can be changed within a certain range while bringing the convex surface portion and the concave surface portion into spherical contact with each other.

  A cylindrical handrail joint is provided at the other end of each movable member, and a bar-shaped or tubular handrail member is attached to the handrail joint and is fastened with a screw or the like.

Japanese Patent Laid-Open No. 11-6267 Japanese Patent Laid-Open No. 2001-254496 Japanese Utility Model Publication No. 5-35940

  In the structure of the conventional handrail universal coupler, the guide hole formed in the convex portion is formed as a long hole (Patent Documents 1 and 2) or a cross hole (Patent Document 3). The movable direction is limited to a two-dimensional (planar) range in which the shaft member can move in the elongated hole or the cross hole. Therefore, when two handrail members are to be connected three-dimensionally (so that the material axis is bent in both the vertical direction and the horizontal direction), at least one movable member is moved around the central axis of the convex surface portion. It is necessary to adjust the relative angle between the connecting member and the movable member while twisting to change the direction of the guide hole.

  In this case, there is no major problem if the cross-sectional shape of the handrail member joined to the movable member is a perfect circle, but the cross-sectional shape of the handrail member is, for example, an oval, an ellipse, or a rounded square or hexagon. If it is non-circular, the continuity of the surface of the handrail member joined to the movable member may be impaired by adjusting the connection angle while twisting the movable member around the material axis. Specifically, for example, the handrail member having the same oval cross section has an event that the long axis is horizontal on the left side of the connecting member and the long axis is inclined on the right side of the connecting member.

  Further, even when the cross section of the handrail member is a perfect circle, the screw position for fixing the handrail member to the handrail joint is uneven on both sides of the connecting member by twisting the movable member around the material axis. This can lead to inconveniences such as a loss of aesthetics.

  The present invention has been made in view of such circumstances. When two handrail members are connected three-dimensionally at an arbitrary angle, the handrail member is easily and accurately not twisted around the material axis. An object of the present invention is to provide a universal handrail connector that can be well connected.

  In order to achieve the above-mentioned object, the basic structure adopted by the handrail universal connector of the present invention is a pair of movable members to which a handrail member is joined at one end, and the relative angle between the pair of movable members is changed. In the universal handrail connector configured by combining the connecting members to be connected in such a manner, the connecting member rotates a vertical semicircular arc that opens laterally around an axis centered in the vertical direction. A concave circumferential surface portion having a shape, and the concave circumferential surface portion is divided into a concave circumferential surface upper half and a concave circumferential surface lower half by a horizontal plane passing through a virtual center point of the vertical semicircular arc, and the concave circumferential surface The upper half and the lower half of the concave peripheral surface are connected so as to be able to rotate in the horizontal direction with respect to each other via a shaft attachment member attached to the vertical axial center position, and the concave peripheral surface A shaft for connecting the movable member to the upper half and the lower half of the concave circumferential surface However, the movable member is provided with a handrail joint portion at one end and a hemispherical shell shape along the concave peripheral surface portion at the other end. A convex hole is formed in the convex surface portion so as to include a center of the convex surface portion, and one movable member of the pair of movable members is an upper half of the concave circumferential surface. The upper shaft member protruding from the part is connected to the upper half of the concave peripheral surface in a state of being inserted through the guide hole of the one movable member, and the other movable member of the pair of movable members is: The lower shaft member projecting from the lower half of the concave peripheral surface is connected to the lower half of the concave peripheral surface in a state of being inserted into the guide hole of the other movable member, and each movable member is Characterized as configured so that each direction can be changed in a state where each convex surface portion is along the concave circumferential surface portion. That.

  That is, the present invention is configured such that each movable member can be independently rotated along two types of rotation axes in the vertical direction and the horizontal direction. By rotating the upper half part of the concave circumferential surface and the lower half part of the concave circumferential surface constituting the connecting member respectively via the shaft attachment members attached to the axial center position in the vertical direction, the upper half part of the concave circumferential surface and The movable members respectively connected to the lower half of the concave peripheral surface can be directed in an arbitrary direction in the horizontal direction as long as they do not interfere with each other.

  Moreover, the long hole-shaped guide hole formed in the convex surface part of each movable member is arrange | positioned vertically, a shaft member is penetrated in the guide hole, and the convex part of each movable member is used as the concave peripheral surface part of a connection member. By sliding along, the movable member can be directed in an arbitrary direction in the vertical direction, with the horizontal axis passing through the concave circumferential surface portion and the virtual center point of the convex surface portion as a virtual rotation axis. Then, by a rotation operation combining these, each movable member can be aligned in an arbitrary direction without twisting each axis.

  The shaft member is preferably a headed bolt that is detachably screwed into the female screw hole formed in the concave peripheral surface portion of the connecting member from the inside of the convex surface portion. When such a screw member is used, it is easy to assemble the connecting member and the movable member, and to adjust and fix the connecting angle, and it is easy to manufacture the parts.

  The guide hole is preferably formed so as to extend from the center of the convex portion to one side and to extend to the other side. Thus, the rotation range of the movable member can be effectively ensured by forming the guide hole asymmetrically from the center of the convex surface portion.

  Further, a detent protrusion that can be engaged in the guide hole is provided at the peripheral edge portion of the shaft member that protrudes from the upper half of the concave peripheral surface and the lower half of the concave peripheral surface, respectively. You may form so that a hole may be restrained vertically. According to this configuration, since the direction of the guide hole is restrained in the vertical direction by the engagement between the anti-rotation protrusion and the guide hole, the movable member is inadvertently twisted while the direction of the movable member is being adjusted. Or a situation in which the fixed handrail member is twisted by the time when the handpiece is gripped and is dangerous to the user can be avoided.

  The handrail joining portion provided at one end of the movable member is formed in a cylindrical shape that can be fitted to the end portion of the handrail member so that the axis of the cylindrical portion matches the axis of the convex surface portion. While being formed, it is preferable that a set screw hole is formed on the side surface. According to this configuration, by matching the cross-sectional shape of the cylindrical portion with the cross-sectional shape of the handrail member, it can be easily joined to handrail members of various shapes, and the joined handrail member can be secured by the set screw. It can be fixed easily and reliably. Although the set screw hole can be provided at a position that is not conspicuous in appearance, according to the present invention, the movable member can be prevented from being twisted about the axis regardless of the direction of rotation. It is easy to avoid a situation in which the set screw hole becomes conspicuous depending on the angle.

  Furthermore, the cylindrical support | pillar junction part which can be fitted by the upper end part of a support | pillar may be provided below the concave periphery surface part in the said connection member integrally with the said recess peripheral surface part. According to this configuration, for example, it becomes possible to reliably join this connecting member to the top of a column having an appropriate cross-sectional shape standing on the floor surface, and the handrail universal connecting device of the present invention can be used. The range expands. In addition, for example, a bracket-like member or the like that protrudes from the wall surface can be joined to the column joint portion.

  In the universal handrail connector of the present invention configured as described above, a connecting member having a concave peripheral surface portion is divided into an upper half portion of the concave peripheral surface and a lower half portion of the concave peripheral surface, and these members rotate in the horizontal direction. Shaft members that are movably connected and have a hemispherical convex surface along the concave peripheral surface of the connecting member projecting from the upper half of the concave peripheral surface and the lower half of the concave peripheral surface Since each of the movable members is independently rotated in the horizontal direction and is independently rotated in the vertical direction. Can do.

  Therefore, it is possible to easily position a plurality of handrail members while accurately adjusting the direction of each handrail member at a portion where the respective handrail members are connected by changing their directions.

  Moreover, since the handrail universal coupler of the present invention is configured so that the movable member does not twist around the axis when changing the direction of the movable member, even if the cross-sectional shape of the handrail member is non-circular, It can connect, without impairing the continuity of the surface of a handrail member.

It is a perspective view which shows the whole structure of the universal connector for handrails concerning embodiment of this invention. It is a disassembled perspective part of the universal connector for handrails. It is a longitudinal cross-sectional view of the said handrail universal coupler. It is a top view explaining the rotation range of the horizontal direction of the movable member in the said universal connector for handrails. It is a side view explaining the rotation range of the vertical direction of the movable member in the said universal connector for handrails. It is an axial direction longitudinal cross-sectional view of the movable member in the said handrail universal coupler.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 6 show a handrail universal coupler according to an embodiment of the present invention. The illustrated universal handrail connector 1 is used in a state where it is attached to an appropriate support 2, a pair of movable members 4 to which a handrail member 3 is joined at one end, and a pair of movable members attached to the support 2. A connecting member 5 that connects the members 4 is combined.

  The connecting member 5 is a substantially rotating body-shaped member having an axial center 91 (see FIG. 3) arranged in the vertical direction. The connecting member 5 is provided with a concave peripheral surface portion 51 for connecting the movable member 4 at the upper portion and at the lower portion. A substantially cylindrical column joint portion 52 that can be fitted to the upper end portion of the column 2 is provided. In the illustrated form, the cross-sectional shape of the support column 2 is circular, and the support column joint portion 52 is formed in a substantially cylindrical shape in accordance with this. The concave peripheral surface portion 51 and the column joint portion 52 are formed integrally with each other so as to coincide with each other. The support column 2 and the support column joint portion 52 are fixed by set screws 53 arranged at two or three side surfaces of the support column joint portion 52. In the illustrated embodiment, a hexagon socket head cap screw is used as the set screw 53.

  As shown in FIG. 3, the concave peripheral surface portion 51 has a shape obtained by rotating a longitudinal semicircular arc that opens laterally around the axis 91 over the entire circumference. However, strictly speaking, the minute ranges near the upper end and near the lower end of the concave peripheral surface portion 51 are opened to the side while the curvature is slightly reduced as compared with the intermediate portion. The outer surface of the concave peripheral surface portion 51 is finished sufficiently smoothly. The top surface of the concave peripheral surface portion 51 is formed to have a spherical shape with a smaller curvature than the concave peripheral surface portion 51.

  The concave peripheral surface portion 51 is divided into a concave peripheral surface upper half 511 and a concave peripheral surface lower half 512 by a horizontal plane 93 passing through a center plane in the height direction, that is, a virtual center point 92 of a longitudinal semicircular arc. Yes. The divided upper half portion 511 and the lower half portion 512 of the concave peripheral surface are connected to each other via a shaft attachment member 6 attached to the shaft center 91 so as to be able to rotate in the horizontal direction. . In the illustrated embodiment, a hexagon socket button bolt is used as the shaft attachment member 6. The shaft attachment member 6 formed of a hexagon socket button bolt is inserted from above through a spring washer 61 and a lubricating resin washer 62 into an insertion hole 53 formed through the shaft center 91 of the upper half 511 of the concave circumferential surface. The leg tip is fastened to the female screw hole 54 formed in the shaft center 91 of the lower half 512 of the concave circumferential surface.

  A shaft member 7 for connecting the movable member 4 protrudes from the concave circumferential surface upper half 511 and the concave circumferential surface lower half 512 one by one. The shaft member 7 is slightly above the dividing surface (horizontal plane 93) in the upper half portion 511 of the concave circumferential surface and slightly more than the dividing surface (same as above) in the lower half portion 512 of the concave circumferential surface. All are provided so as to protrude from the lower position toward the virtual center point 92 of the longitudinal semicircular arc.

  In the illustrated embodiment, a headed bolt with a hexagonal hole is used as the shaft member 7. The shaft member 7 made of the bolt is detachable from the inner side of the movable member 4 to be described later, into female screw holes 55 and 56 formed at the positions of the upper half 511 and the lower half 512 of the concave circumferential surface. It is concluded to.

  The movable members 4 are both the same member, each having a substantially cylindrical handrail joint portion 41 that can be fitted to the end portion of the handrail member 3 at one end, and the concave peripheral surface portion of the connecting member 5 at the other end. The convex part 42 connected with 51 is provided.

  In the illustrated embodiment, the handrail member 3 has a circular cross-sectional shape, and the handrail joint portion 41 is formed in a substantially cylindrical shape in accordance with this. The handrail joint portion 41 and the handrail member 3 are fixed by set screws 43 disposed at two or three side surfaces of the handrail joint portion 41. In the illustrated embodiment, a round countersunk wood screw is used as the set screw 43, and is fixed to two set screw holes 44 formed facing the side surface of the handrail joint portion 41.

  The convex surface portion 42 is a hemispherical shell-shaped portion having a substantially constant thickness, and the outer surface thereof is a hemispherical convex surface having substantially the same diameter as the vertical semicircular arc that defines the peripheral surface shape of the concave peripheral surface portion 51. Smooth finish. Further, the inner surface of the convex portion 42 is concentric with the outer surface and forms a slightly small-diameter hemispherical concave surface. That is, the virtual center point of the convex surface portion 42 matches the virtual center point 92 of the vertical semicircular arc. The convex surface portion 42 and the handrail joint portion 41 are formed integrally with each other so as to coincide with each other.

  An elongated guide hole 45 is formed in the convex surface portion 42, and the shaft member 7 is inserted into the guide hole 45. The guide hole 45 is asymmetric including the center of the convex surface portion 42 (the center of the circle when the hemispherical convex surface is viewed from the front / the portion protruding from the tip in the axial direction of the movable member 4), that is, long from the center to one side, It is formed to extend to the other side.

  Then, one of the pair of movable members 4 includes an upper shaft member 7 projecting from the upper half 511 of the concave peripheral surface of the connecting member 5 in the guide hole 45 of the one movable member 4. In the inserted state, it is connected to the upper half 511 of the concave circumferential surface. In addition, the other movable member 4 has a lower shaft member 7 protruding from the lower half 512 of the concave circumferential surface and is inserted into the guide hole 45 of the other movable member 4. Connected to half 512.

  That is, in the exemplary embodiment, the shaft member 7 formed of a hexagon socket head cap screw is inserted into the guide hole 45 of each convex surface portion 42 via the spring washer 71 and the flat washer (or spherical washer) 72 from the inside of each movable member 4. The leg tips are fastened to female screw holes 55 and 56 formed in the concave circumferential surface upper half 511 and the concave circumferential surface lower half 512, respectively. Adjustment of attachment / detachment and tightening adjustment of the shaft member 7 made of a hexagon socket head bolt is performed by inserting a tool such as a hexagon wrench from the inner surface side of the convex surface portion 42, that is, the handrail joint portion 41 side. Therefore, the handrail member 3 is joined to the handrail joining portion 41 after the movable member 4 is positioned in a predetermined direction as described above.

  4 and 5 are diagrams illustrating a range in which the movable member 4 can be rotated by the above-described configuration.

  The concave peripheral surface portion 51 of the connecting member 5 is divided into two parts in the vertical direction and is connected so as to be rotatable around the vertical axis 91, and the divided upper and lower parts (the concave half surface upper half 511 and the concave half surface lower half) 512), the movable members 4 are connected to each other. Therefore, as shown in FIG. 4, in the horizontal direction, each movable member 4 can be rotated 360 degrees in an arbitrary direction within a range where they do not interfere with each other. it can.

  Further, the elongated hole-shaped guide hole 45 formed in the convex portion 42 of each movable member 4 is oriented vertically, and the shaft member 7 is inserted into the guide hole 45 so that the vertical direction is as shown in FIG. In addition, each movable member 4 directs its axis in an arbitrary direction within a range in which the shaft member 7 can move in each guide hole 45 while keeping the convex portion 42 along the concave peripheral surface portion 51 of the connecting member 5. Can do. Since the rotation axis of each movable member 4 becomes a horizontal axis in the direction orthogonal to the paper surface passing through the virtual center point 92 of the concave peripheral surface portion 51 and the convex surface portion 42, both the movable members 4 are movable when the axes of both the movable members 4 are horizontal. The axis of the member 4 continues in a straight line as shown.

  In the exemplary embodiment, as shown in FIG. 6, the guide hole 45 has a length that can move the shaft center of the shaft member 7 by about 28 degrees on the upper side in the figure, about 17 degrees on the lower side in the figure, and about 45 degrees in total. Is set. As shown in FIG. 3, the movable member 4 connected to the upper half 511 of the concave circumferential surface is provided with a guide hole 45 so that the movable member 4 can be rotated downward from the horizontal position. About the movable member 4 connected with the lower half part 512 of a surrounding surface, the guide hole 45 is arrange | positioned so that the movable member 4 can be rotated upwards from a horizontal position. Naturally, if the length of the guide hole 45 is increased, the rotation range of the movable member 4 is also expanded. However, in a general handrail construction site, a rotation range of about 45 degrees is secured in the vertical direction. If so, there is no particular inconvenience in practical use.

  As described above, according to the present invention, the vertical rotation axis (the axis 91 of the connecting member 5) and the horizontal rotation axis (the horizontal axis passing through the virtual center point 92 of the concave peripheral surface portion 51 and the convex surface portion 42). , The movable members 4 can be independently rotated in any direction. In this case, the feature unique to the present invention obtained from the above-described configuration is that the movable member 4 does not twist around the axis of the movable member (handrail member) regardless of which direction it faces. Therefore, the set screws fastened to the two side surfaces of the handrail joint portion 41 of the movable member 4 are always held at positions facing each other at the same height regardless of the posture of the movable member 4.

  In order to ensure that the movable member 4 is not twisted, it is engaged in the guide hole 45 at the base end peripheral edge portion of the shaft member 7 in the concave peripheral surface upper half 511 and the concave peripheral surface lower half 512. It is also preferable to form possible detent projections 57, 58, respectively. In the illustrated embodiment, the peripheral edge portions of the female screw holes 55 and 56 formed in the concave circumferential surface upper half 511 and the concave circumferential surface lower half 512, respectively, are bulged in a reverse U-shape or U-shape when viewed from the front. The width between both side edges of the bulging portion is formed so as to fit into the guide hole 45. By providing such anti-rotation protrusions 57 and 58 and engaging with the guide hole 45, the guide hole 45 is always restrained so as to be vertically oriented.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be carried out by appropriately modifying details within the scope not departing from the gist of the invention. For example, the cross-sectional shape of the handrail joint portion 41 provided on the movable member 4 may be formed in an oval shape, an oval shape, or a non-circular shape such as a rounded square or hexagon according to the cross-sectional shape of the handrail member 3. Good. In that case, the non-circular cylindrical portion may be connected to the convex surface portion 42 via the connection portion having an appropriate shape so as to coincide with each other.

  Similarly, the cross-sectional shape of the column joint portion 52 provided in the connecting member 5 is not limited to a circle, but may be an oval, an ellipse, or a non-circular shape such as a rounded square or a hexagon. In that case, the non-circular cylindrical portion may be connected to the concave peripheral surface portion 51 via a connection portion having an appropriate shape. However, the support column 2 and the connecting member 5 do not necessarily need to coincide with each other. The connecting member 5 may be connected to, for example, a bracket-like member or the like that protrudes from the wall surface within a range that does not hinder the rotation operation of the concave peripheral surface portion 51.

  Further, the shaft attachment member 6 that connects the upper half 511 and the lower half 512 of the connection peripheral surface of the connection member 5, the shaft member 7 that connects the connection member 5 and the movable member 4, the movable member 4 and the handrail. The screw member for fastening the member 3 and the screw member for fastening the connecting member 5 and the support column 2 are appropriately selected from known general screw members in consideration of the shape and material of each member. That's fine. The shaft member 7 that connects the connecting member 5 and the movable member 4 is previously planted in a fixed state on the concave peripheral surface portion 51 side of the connecting member 5, and its tip is inserted into the guide hole 45 of the movable member 4 from the outside. It may be inserted and an appropriate retaining means may be provided from the inner surface side of the convex surface portion 42.

  The present invention is used for connecting rod-shaped or tubular handrail members installed in various buildings and facilities, etc. In addition, similar linear structural materials and temporary materials are sequentially laid while changing the direction. Can be widely used for handing over.

DESCRIPTION OF SYMBOLS 1 Handrail universal connector 2 Support | pillar 3 Handrail member 4 Movable member 41 Handrail joint part 42 Convex part 44 Set screw hole 45 Guide hole 5 Concave surface part 511 Concave surface upper half 512 Concave surface lower half 52 Column joints 55, 56 Female threaded holes 57, 58 Anti-rotation projection 6 Axial member 7 Axle member 91 Axis center 92 Virtual center point 93 Horizontal plane

Claims (6)

In the handrail universal coupler configured by combining a pair of movable members to which a handrail member is joined at one end and a coupling member that couples the pair of movable members so that the relative angle of each pair can be changed.
The connecting member includes a concave peripheral surface portion having a shape formed by rotating a longitudinal semicircular arc that opens laterally around an axis disposed in a vertical direction,
The concave peripheral surface portion is divided into a concave peripheral surface upper half and a concave peripheral surface lower half by a horizontal plane passing through a virtual center point of the vertical semicircular arc,
The concave peripheral surface upper half and the concave peripheral surface lower half are connected so as to be able to rotate in the horizontal direction with respect to each other via a shaft attachment member attached to the axial center position in the vertical direction,
A shaft member for connecting the movable member is protruded from the upper half of the concave circumferential surface and the lower half of the concave circumferential surface, one each toward the virtual center point of the vertical semicircular arc. ,
The movable member includes a handrail joint at one end and a hemispherical convex surface along the concave peripheral surface at the other end.
In the convex surface portion, a long hole-shaped guide hole is formed so as to include the center of the convex surface portion,
One movable member of the pair of movable members is formed on the concave circumferential surface in a state where an upper shaft member protruding from the upper half of the concave circumferential surface is inserted into the guide hole of the one movable member. Connected to the half,
The other movable member of the pair of movable members has the concave peripheral surface in a state where a lower shaft member protruding from the lower half of the concave peripheral surface is inserted into the guide hole of the other movable member. Connected to the lower half,
The movable connector for handrails, wherein each movable member is configured to be able to change the direction of each convex surface portion along the concave circumferential surface portion. The handrail universal coupler according to claim 1,
The handrail universal connector, wherein the shaft member is a headed bolt that is detachably screwed into the female screw hole formed in the concave peripheral surface portion of the connecting member from the inside of the convex surface portion. In the handrail universal coupler according to claim 1 or 2,
The handrail universal connector, wherein the guide hole is formed so as to extend from the center of the convex portion to one side and to extend to the other side. The handrail universal coupler according to any one of claims 1 to 3,
Non-rotating protrusions that can be engaged in the guide holes are provided at the base peripheral edge portions of the shaft member that project from the upper half of the concave peripheral surface and the lower half of the concave peripheral surface, respectively. A universal handrail coupler characterized by being formed so as to be restrained in a vertical direction. In the universal connection tool for handrails of any one of Claims 1-4,
The handrail joint portion is formed in a cylindrical shape that can be fitted to the end portion of the handrail member, and is formed so that the axial center of the cylindrical portion matches the axial center of the convex surface portion. A universal handrail connection tool, wherein a set screw hole is formed. In the universal connector for handrails of any one of Claims 1-5,
A cylindrical hand column joint that can be fitted to the upper end of the column is provided integrally with the concave surface on the lower side of the concave surface of the connecting member. .

Images