The present invention relates to a coupling device for connecting structural members. The coupling device can take up the difference in thickness of connected structural members without mechanical processing. It can also take up the variation in depth and deviation from straightness, which can occur during the construction procedure while keeping the strong connection between the connected structural members, which is easy to fabricate at low cost, comprises a coupling case that has connecting slots, in which the structural members to be connected are placed, and fillers that are placed inside the slots, and the wedges that are placed between the fillers and the connected structural members.
Bolted connection has been widely used as the means of structural connection in civil and architectural construction fields such as column splices, beam-to-column connections, beam splices, and brace connections. Bolted connection requires a large number of holes to be drilled in the connected structural members and the splice plates or brackets that are placed at one or both sides of the connected structural members to connect the structural members using bolts and nuts.
However, the large number of holes required for bolted connection cause problems such as reduced section, stress concentration, reduction in the energy absorption capacity, and increase in installation time under dangerous work environment. Moreover, slip between connected structural members may occur under tension or compression force, because the diameter of bolts is always smaller than that of holes. To prevent slip and stress concentration from occurring, friction-type connection has been used, in which high clamping force is induced for the friction force at the connected surface to resist the applied force. However, the problems of bolted connection can not be solved completely.
To solve the problems of bolted connection, the inventors of the present invention have disclosed a connecting technique (PCT/KR01//00572), in which the coupling device comprises a coupling case with connecting slots (20), in which the structural members to be connected (10) are placed, and wedges (30) that are inserted into the space between the coupling case and the connected member as shown in
The coupling device of PCT/KR01/00572 does not have the problems due to bolt holes such as reduced section, stress concentration, reduction in the energy absorption capacity, because it does not require bolt holes to be drilled in the connected structural members. The fabrication cost of the coupling device may be less than that of bolted connection which needs bolts, drilling, and connection plates such splice plates or brackets. Moreover, the coupling device is easy to install compared to bolted connection which needs installation of a large number of bolts reducing the construction time, labor cost, and accidents due to work at high places. However, the coupling device has some problems as follows:
First, it takes lots of cost and labor to mechanically process the connecting slots of the coupling case to match the dimensions of the wedge and the connected member with precision. Moreover, installation time may be increased, because it is not easy to insert the wedge between the coupling case and the member which are made with precision.
Second, since dimensional tolerances are allowed in the production of wide-flange beams, the coupling device must be able to take up the variation in the thickness of the beam flanges for easy and safe construction. However, there is an intrinsic problem that the variation can not be taken up using the connecting slot of the coupling case and the wedge only.
Third, there are limits to the application of the coupling device in case of any difference in depth and/or deviation from straightness at a connection.
The present invention is devised to solve the problems of the coupling device as above mentioned. It is the objective of the present invention to provide an improved coupling device for structural steel connections that is easy to fabricate at low cost, and can take up any difference in thickness of connected structural members without mechanical processing, any variation in depth, and deviation from straightness which can occur during the construction procedure while keeping the strong connection between the connected structural members. For this purpose, the present invention provides a coupling device which comprises a coupling case that has connecting slots, in which the structural members to be connected are placed, and a pair of fillers that are placed inside the connecting slots to touch the surface of the slots, and the wedges that are placed between the fillers and the connected structural members.
In the coupling device of the present invention, the connecting slot of the coupling case is formed as a round hole whose diameter is larger than the width of the slit for the insertion of the connect member making it easier to fabricate than the connecting slot of the previous coupling device in which the two slope surfaces have to be mechanically processed with precision. The filler that is placed in the connecting slot has an outer surface that touches the coupling case and an inner surface that touches the wedge. The inner surface of the filler has slope side 1 and slope side 2 which are tapered outwards. The wedge has an outer surface that has slope side 1 and slope side 2 corresponding to the slope side 1 and slope side 2 of the filler and an inner side that touches the member.
In another Preferred Embodiment of the present invention, said wedge is divided along the borderline between slope side 1 and slope side 2, and springs are placed between the divided wedges to spread them.
In another Preferred Embodiment of the present invention, said wedge is divided transversely with the outer surfaces of the divided wedges formed to be tapered outwards, and the inner side of said filler is tapered inwards corresponding to the outer surface of said wedge. A space adjuster is provided between the divided wedges to spread them. After the coupling device is placed, the space adjuster is modulated to spread the divided wedges securing better wedge action.
In another Preferred Embodiment of the present invention, to ensure firm contact between the wedge and the member, which secures safety of the coupling device, a stud is attached to the surface of the member, and a corresponding hole is formed on the inner surface of said wedge.
Practical and presently preferred embodiments of the present invention, which may make modifications and improvements within the scope of the present invention, are illustrated using the figures.
As shown in
In the present invention, said members (100) include various structural steel members used as beams or columns of steel building structures, structural steel members used in bridge structures, nonferrous metals, and FRP members without any limitation in the material, size, or shape. Although said members can be connected using splice connections or intersecting connections, only splice connections are shown in the illustrations in the following.
The coupling case (200) of the coupling device of the present invention has at least one connecting slot (210), which is formed to have a round hole whose diameter (D) is larger than the width (d) of the slit (214) for the insertion of the connect member as shown in
The width of the said coupling case (200) can be made to match the width of the connected member such as the flange width of wide-flange beams. The connecting slot (210) has a round hole that is open at both ends for fillers and wedges to be inserted and a slit (214) for a connected member to be inserted.
The connecting slots (210) of said coupling case (200) can be formed in symmetry as shown in
Said filler (300) can be made in various sizes to take up any variation in the thickness of the structural members, and the inner surface (320) that touches the wedge is mechanically processed to reduce the coefficient of friction.
Moreover, said filler (300) can be made longer than the wedge (400) to take up the dimensional deviation by adjusting the length of insertion. The width and thickness of the inner surface (320) of the filler (300) can be made to be smaller at one end for easier insertion.
The outer surface (410) of said wedge (400) is mechanically processed to reduce the coefficient of friction. If not shown in a figure, the inner surface (420) that touches the member (100) is treated to be rough or have serrations of projection type.
In this Preferred Embodiment, a stud (110) is attached to the surface of the member (100) that is placed in the connecting slot (210) of the coupling case (200), and a hole (422) corresponding to the stud (110) is formed on the inner surface of the wedge (400) that touches the member. The rest are the same as those of the first Preferred Embodiment.
In this Preferred Embodiment, improved safety can be secured by the bearing connection between the stud (110) and the hole (422) in addition to the initial friction of the contact surface when slip between the member (100) and the wedge (400) occurs due to insufficient contact.
The structural members (100) can move in the connecting slots (210) to some extent and rotate in either direction about the center of the round hole of the connecting slot (210) as shown in
In this Preferred Embodiment, the coupling case (200) and the fillers (300) are the same as those of the first and second Preferred Embodiments. The difference is that one wedge (400) on either side of the member (100) is divided in half; that is, the wedge (400) of this Preferred Embodiment is divided into two parts (400a, 400b) along the borderline between slope side 1 (412) and slope side 2 (414), which is transverse to the direction of the member, and springs (400c) are placed between the divided wedges (400a, 400b) to spread them in the connecting slot (210) of the coupling case (200) inducing close contact between the wedges (400a, 400b) and the member (100).
In this Preferred Embodiment, while the coupling case (200) is the same as those of the first to third Preferred Embodiments, the wedge (400) and the filler (300) have different shapes. Unlike that of the third Preferred Embodiment, the wedge (400) is divided into two parts in the direction of the member (transverse to the direction of the wedge). The outer surface of the divided wedges (400d, 400e) is formed to be tapered outwards as shown in
The coupling device of the present invention can connect structural members by a wedge action as the wedge and the member are brought in to close contact by inserting the filler or spreading the wedge after the wedge and the member are placed in the connecting slot of the coupling case. The coupling device of the present invention makes an easy installation possible at the construction site by taking up any difference in thickness of the connected structural members and any variation in depth at the connection. The insertion of the filler brings the wedge into close contact with the member securing the wedge action. If a stud is attached to the member, the stud secures the wedge action when the wedge is not in close contact with member. Split-type wedges can easily take up any difference in member thickness and secure the wedge action by the spreading force of elastic springs or space adjusters reducing the construction time and labor costs greatly compared with the conventional bolted connection and the coupling device of the previous invention.
Number | Date | Country | Kind |
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2003-26996 | Apr 2003 | KR | national |
Number | Date | Country | |
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Parent | PCT/KR04/00984 | Apr 2004 | US |
Child | 11262293 | Oct 2005 | US |