The present invention relates to a fastening device used at the time of fixing a pillar to a foundation or fastening a cross beam to a pillar in various wooden structures.
Wooden framed buildings, mainly employed in small-scaled buildings such as residential houses, have been spreading in larger-scaled buildings such as a public facility since glue-laminated wood with a large cross section has been manufactured and introduced recent years. In domestic wooden houses, timber framework method using a foundation, pillars, beams, and the like is the mainstream. However, in the case of larger-scaled buildings, the Rahmen (rigid-frame) structure in which glued laminated timber having a large cross section is assembled in a portal type or the like is often employed. In the wooden Rahmen structure, it is necessary to assure rigidity of a part that fastens members such as a foundation and a pillar or a pillar and a beam, therefore as disclosed in Patent Literature 1 have been proposed.
Patent Literature 1 discloses a technique of connecting a vertical lumber piece corresponding to a pillar and a lateral lumber piece corresponding to a beam via a basic metal fitting and an accessory metal fitting and forming a tapered part and a reception part that are paired, at both upper and lower ends of the basic and accessory metal fittings. One of the metal fittings is attached to a side surface of the vertical lumber piece, and the other metal fitting is attached to an end surface of the lateral lumber piece. After that, by inserting the tapered parts in the metal fittings to the reception parts of the other metal fittings, the lateral lumber piece is coupled to the vertical lumber piece. According to the technique, the tapered part has an inclined surface, so that the metal fittings are naturally closely attached to each other. Therefore, the rigidity of the fastening part can be assured effortlessly. If attachment of the metal fittings becomes loose due to distortions of the lumber pieces through natural causes over time, the rigidity deteriorates, and the Rahmen structure cannot be maintained. Therefore, the metal fittings are fixed to the members via lag screws.
The lumber piece has poor toughness against external forces and is breakable such that when a load exceeds a limit, a crack promptly develops, and the lumber piece is broken all at once. The lumber is produced by nature such that strength of the lumber varies due to various factors, such as, the presence/absence of a knot, water content, and the like. To address the features peculiar to the lumber, a technique as disclosed in Patent Literature 2 is proposed. A vibration damping structure of fastening two members such as a pillar and a beam by using an elasto-plastic damper made of metal is disclosed. The elasto-plastic damper has an H shape obtained by connecting two flanges by a web, and a notch is formed in the web. When the web is elasto-plastic deformed at the time of an earthquake, energy is absorbed, and breakage of the lumber can be prevented.
Similar techniques to Patent Literature 2 are described in Patent Literatures 3 and 4. Literature 3 discloses a technique regarding a structure of fixing a wooden pillar to a pillar base part, which is characterized in that an anchor member buried in a foundation to fix a pillar is provided with a vibration damping function. Literature 4 is directed to attenuate quakes quickly at the time of an earthquake in a wooden structure and is characterized in that a pillar and a beam are fastened by a joining metal fitting having a plate spring shape.
Patent Literature 1: Japanese Patent Application Laid-open Publication No. 2007-132168
Patent Literature 2: Japanese Patent Application Laid-open Publication No. 2005-61058
Patent Literature 3: Japanese Patent Application Laid-open Publication No. 2002-256628
Patent Literature 4: Japanese Patent Application Laid-open Publication No. H04-261935
As described above, wood has inherent problems, such as, being breakable and variations in strength. To mitigate the problems, an effective measure is to absorb energy by deforming a fastening elasto-plastic device, as disclosed in Patent Literature 2. However, when the fastening device has too much flexibility, rigidity becomes insufficient. Unignorable deformations may be caused by daily load fluctuations and, moreover, habitation may also be influenced by the deformations. Consequently, a fastening device used in a rigid-frame structure has, preferably, rigidity, and during earthquakes displays flexibility so that a crack in a member can be prevented.
If a building experiences the effects of an earthquake such that a fastening device is plastic-deformed, the fixing between the fastening device and a joint between the fastening device and a wooden piece becomes loose. The post-plastic-deformed device would not have the benefit of the pre-plastic-deformed device during subsequent aftershocks, and the building may be largely damaged. Therefore, repeated excessive loads should be considered in the design of the fastening device. Further, costs and time related to repairs and burdens of the occupants for the repairs when the aftershocks stop should be low.
The present invention has been made to provide a solution to address these issues and a design of a fastening device with an objective to assure rigidity of a fastened part and, moreover, when excessive loads are applied, to prevent structural damage.
An invention described in claim 1 for solving the problem relates to a fastening device for fastening a supporting member and a connecting member that are adjacent to each other such as a pair of a foundation plate and a pillar or a pair of a pillar and a cross beam, including: a bearing body disposed in a space in which the supporting member and the connecting member face each other; a plurality of shock absorbing bodies disposed near outer rims in the space; anchoring implements embedded in the supporting member and/or the connecting member to fix the bearing body and the shock absorbing body; and a bolt for fixing the bearing body and the shock absorbing body. The bearing body includes a basic plate that is in surface contact with the supporting member, a mounting plate that is in surface contact with the connecting member, and a connecting section connecting the basic plate and the mounting plate in substantially a center of the space, and the shock absorbing body has elasticity to generate reaction force in accordance with displacement of the space, one end of the shock absorbing body is fixed to the basic plate or any of the anchoring implements in the supporting member, and the other end is fixed to the mounting plate or any of the anchoring implements in the connecting member.
The fastening device according to the present invention is provided to integrate adjacent two members such as a foundation and a pillar or a pillar and a beam in various wooden structures and use in a wooden rigid-frame structure where members are assumed to be firmly fastened. The supporting member refers to a member closer to the ground out of two members to be fastened. The connecting member refers to a member supported in the air by the supporting member. The present invention relates to a case of fastening wooden pieces including glued laminated timbers such as a pillar and a beam and also a case of fastening a wooden piece to concrete or a steel member. For convenience, the concrete or the steel member will be also called supporting members. In the space between two members to be fastened, side surfaces or end surfaces of the members face each other with a gap therebetween. In this space, the bearing body and the shock absorbing body are positioned.
The bearing body includes a basic plate that is in surface contact with the supporting member, a mounting plate that is in surface contact with the connecting member, and a connecting section integrating the basic plate and the mounting plate. The bearing body is generally made of metal and has an H-like shape. Only one bearing body is disposed in the center of the border of the two members and has the function of transmitting axial force applied to the connecting member to the supporting member. Each of the basic plate and the mounting plate is attached to the supporting member and the connecting member via bolts, respectively. Thereby, in both of the plates, circular holes to which the bolts are inserted are formed.
The connecting section is provided to maintain the gap between the basic plate and the mounting plate and that the connecting section is assumed to have a sufficient strength at least in the compression direction. The connecting section transmits the axial force applied to the connecting member to the supporting member. It is also assumed that the connecting section has a bendable structure so that, in the case where a bending moment acts on the connecting member, the mounting plate can be displaced in accordance with the moment. Consequently, a block having a large cross section and is unbendable cannot be used as the connecting section.
A configuration example of the connecting section may be a simple plate connecting the center of the basic plate and the center of the mounting plate. By locally forming notches in both side surfaces of the plate, bendability to an excessive load is assured. The parts in which notches are formed still need to be sufficiently rigid such that only minor displacement can be found against a usual axial force. For a part to which only compressed load is normally applied such as a lower part of a pillar, the connecting section may have a detachable structure.
The shock absorbing bodies are disposed near the outer rim in the space where the supporting member and the connecting member face each other and are attached so as to straddle the supporting member and the connecting member. At least two shock absorbing bodies are necessary for a single fastening part and are disposed symmetrically around the center of the bearing body as a reference. Therefore, when the fastening part has an elongated rectangular shape, the shock absorbing bodies are disposed so as to sandwich the center of the bearing body. The shock absorbing body has the function of absorbing energy and displacement to lessen the load applied to the members by being elastically or plastically deformed when external force is received. The shock absorbing body also transmits axial force and shear force. The shock absorbing body has to have rigidity to a degree that it is substantially regarded as a rigid-frame structure at an ordinary load, and a member having a small spring constant is not preferred.
An example of the shock absorbing body is a simple plate spring obtained by just bending a steel plate in a U shape. When one of outside surfaces of the plate spring is attached to the supporting member and the other outside surface is attached to the connecting member, an intermediate semicircular part functions as a spring. By changing the length, thickness, and the like of the plate spring, the spring constant can be changed. Optimum design according to load conditions is easy. The shape of the plate spring is not limited to the U shape but an arbitrary shape such as a Z shape or a cylindrical shape can be selected. In addition, a perforated plate obtained by cutting out a plurality of parts in a steel plate can be also used as the shock absorbing body.
The shock absorbing body can be directly attached to the supporting member and the connecting member or attached to the basic plate and the mounting plate of the bearing body. Since the basic plate and the mounting plate are integrated with the supporting member and the connecting member, even when the shock absorbing bodies are attached so as to straddle the basic plate and the mounting plate, the function is unchanged. In this case, however, the basic plate and the mounting plate are set to have the same size as that of the end surface shape of the connecting member or the like, so that the shock absorbing bodies can be disposed properly.
The anchoring implements are used to firmly integrate the bearing body and the shock absorbing body with a member. Since large loads are expected to be applied to the bearing body and the shock absorbing body, sufficient consideration is necessary also for the attachment to the member, and a simple wood screw or the like cannot be used from the viewpoint of strength. When a member is made of wood, a anchoring implement such as a lag screw is disposed in the member, and the bearing body or the shock absorbing body is attached via the anchoring implement. A female screw is used in an end surface of the anchoring implement, and the bearing body or the shock absorbing body is made to come into contact with the end surface. After that, a bolt is inserted and fastened, so that the bearing body or the shock absorbing body is integrated with the member via the anchoring implement. Examples of the anchoring implement include not only the lag screw but also a deformed bar.
An invention described in claim 2 relates to a structure of a connecting section of a bearing body, and the connecting section has a lower arm projected from the basic plate, an upper arm projected from the mounting plate, and a pin penetrating the lower arm and the upper arm and axially supporting the basic plate and the mounting plate so as to be rotatable.
At least two lower arms or upper arms are arranged in parallel with a predetermined gap therebetween, the other arms are disposed so as to be engaged with the arranged lower or upper arms. When the other arms are fit in the arranged arms and a pin having a circular cross section is inserted so as to penetrate all of the arms, the basic plate and the mounting plate are integrated via the pin. Each of the upper and lower arms is rotatable about the pin as a fulcrum, thereby realizing swing of the basic plate and the mounting plate.
With such a configuration, the bearing body can transmit axial force and shear force but cannot transmit bending moment. Consequently, the role of the bearing body and that of the shock absorbing body can be divided and each of the bearing body and the shock absorbing body can be optimally designed according to a load condition. In the case of using the bearing body lying sideways, a hook can be used as the upper arm of the mounting plate. The hook has a shape in which a retaining groove is cut upward from bottom and retains the pin deep inside of the retaining groove. Consequently, separation between the basic plate and the mounting plate is easily accommodated.
An invention described in claim 3 relates to an example of the shock absorbing body. The shock absorbing body is a stud bolt in which a left screw is used at one end and a right screw is used at the other end, and internal screws in which the stud bolts are screwed are provided in outer rims of the basic plate and the mounting plate. In the present invention, the stud bolts are used as the shock absorbing bodies. The stud bolt is also called a full thread bolt and is obtained by forming a male screw in a simple round rod. In the present invention, however, a left screw is used at one end, and a right screw is used at the other end. Naturally, the stud bolt is disposed so as to connect the basic plate and the mounting plate, and its both ends are fixed to the respective plates. It is necessary to make the stud bolt to perform the original function by using a material that tends to cause an elasto-plastic deformation such as a low-yield-point steel.
The internal screw is a female screw in which the stud bolt is screwed and is positioned concentrically with both of the basic plate and the mounting plate. Since the right and left screws are used in the stud bolt, one of the internal screws in the basic plate and the mounting plate is set as the left screw, and the other internal screw is set as the right screw. Although the internal screws may be simple female screws, to assemble or detach the stud bolt, the internal screw may take a structure to be split by a diameter line of the internal screw. The disposing method for the stud bolt, the number of stud bolts to be used, and the like can be freely determined.
An invention described in claim 4 also relates to an example of the shock absorbing body. The shock absorbing body is a shaft having a flange-shaped or groove-shaped stepped part in a side peripheral surface near both ends, and a restrainer retaining the step part is provided on outer rim of the basic plate and the mounting plate. In the present invention, as the shock absorbing body, a shaft (rod member) is used and disposed so as to connect the basic plate and the mounting plate. The stepped part is provided to attach the shaft to the basic plate or the mounting plate, is a flange-shaped part projected from the side peripheral surface of the shaft or a groove-shaped part obtained by cutting the side peripheral surface, and is formed near the end. The restrainer is attached to the basic plate and the mounting plate and is a part in which the stepped part is fit to retain the stepped part securely.
As an example of the stepped part and the restrainer combination, the flange-shaped stepped part is provided at both ends of the shaft, and the groove-shaped restrainers in which the stepped parts are fit are attached to the basic plate and the mounting plate. In the configuration, the restrainer has to be detachable so that assembly and detachment of the shaft can be performed smoothly. In addition, also with respect to the shaft, it is necessary to make the shaft display the original function by using a material that tends to cause an elasto-plastic deformation such as a low-yield-point steel.
By constructing the fastening device by the bearing body and the shock absorbing body or the like as in the invention of claim 1, the compressive load acting between the supporting member and the connecting member is transmitted directly by the bearing body, and the rigidity of the fastened part can be assured. Although the bending moment acting on the connecting member is transmitted to the supporting member via the shock absorbing bodies, since plate springs or the like are used as the shock absorbing bodies, large spring constants can be easily obtained and, moreover, at least two shock absorbing bodies are disposed. Consequently, deformation caused by ordinary load fluctuation is small, and the supporting member and the connecting member that are fastened can be regarded as a rigid-frame structure. Further, when a shock load different from the ordinary load is applied during an earthquake or the like, the energy is absorbed by deformation of the shock absorbing bodies. Consequently, the load acting on major members and the connecting members is lessened, breakage such as a crack is prevented, and damage to a building is mitigated.
Also when a shock load is applied, if plastic deformation does not occur in the bearing body and the shock absorbing body, the performance does not deteriorate after that. Even if plastic deformation occurs, a load applied to members, bolts, and the like is lessened due to the deformation, crack of the members, loosening of the bolts, and the like can be prevented, and the strength of the part around the fastening device does not deteriorate. Moreover, at the time of restoring a building after an earthquake, only the bearing body and the shock absorbing body would be replaced, and the pillar and the like are maintained as they are. Consequently, repair costs and time can be minimized and the inconveniences to occupants are reduced.
As the invention described in claim 2, with respect to the connecting section of the bearing body, by making the basic plate and the mounting plate rotatable by interposing the arms and the pin, the bearing body does not transmit the bending moment. As a result, the functions of the bearing body and that of the shock absorbing body are clearly divided. Both of the bearing body and the shock absorbing body can be optimally designed according to a load condition. Sufficient rigidity is assured and, moreover, during an earthquake or the like, flexibility can be reliably achieved. Since the mounting plate is rotatable, even when a shock load is received, the connecting section is not plastic-deformed. As a repair after that, it is sufficient to replace only the shock absorbing body.
As the invention described in claim 3, by using the stud bolts as the shock absorbing bodies and changing the material and the cross section of the stud bolts, the optimum fastening device that is capable of freely adjusting the behavior with respect to the load and that is adapted to circumstances of a place where it is used can be provided. As the invention described in claim 4, also in the case of using the shaft as the shock absorbing body, by changing the material and the cross section of the shaft, a similar effect can be anticipated.
a) shows a perspective view of a fourth shape example of the entire fastening device, using shafts as the shock absorbing bodies, and (b) shows a perspective view of a use state of the fourth shape example of the entire fastening device;
The pillar 51 fastened to the foundation plate 42 corresponds to a connecting member and is fixed in an upright state. The pillar 51 is made of a glued laminated timber to form an elongated cross section therein. To attach the fastening device, four anchoring implements are screwed in the lower end surface of the pillar 51. The anchoring implements are typically lag screws 55 made of a metal and having a columnar shape. In each of the lag screws 55, a spiral projection 56 is formed in a side peripheral surface, and a female screw 57 is formed in the lower end surface. On the bottom surface of the pillar 51, preparation holes 53 to which the lag screws 55 are screwed are formed.
The fastening device has an elongated configuration that fits the lateral cross section shape of the pillar 51. A bearing body 11a is positioned in the center of the fastening device, and is sandwiched by shock absorbing bodies 38a. The bearing body 11a is a structure obtained by integrating a basic plate 12 to be in contact with the foundation plate 42 and a mounting plate 14 to be in contact with the pillar 51 by a connecting section. The bearing body 11a is generally made of metal and transmits axial force and shear force acting on the pillar 51 to the foundation 41. In the surface of the basic plate 12 and the mounting plate 14, circular holes 13 are formed. When bolts 54 are inserted in the circular holes 13 toward the female screws 47 and 57 in the foundation plate 42 and the lag screws 55, the foundation plate 42 and the pillar 51 are integrated via the bearing body 11a.
The connecting section of the bearing body 11a is constructed with a lower arm 21, an upper arm 23, and a pin 22. Two lower arms 21 extending from the top surface of the basic plate 12 are arranged in parallel with a gap in between. The upper arm 23 extending from the bottom surface of the mounting plate 14 enters between the two lower arms 21. The pin 22 is inserted so as to penetrate an end part of each of the lower and upper arms 21 and 23, and the arms 21 and 23 are coupled rotatably about the pin 22 as a fulcrum. Therefore, when the foundation plate 42 and the pillar 51 are integrated only by the bearing body 11a and the wide side surface of the pillar 51 is seen, the pillar 51 can be easily tilted in the lateral directions.
Each of shock absorbing bodies 38a is a plate spring obtained by bending a steel plate in a U shape and is sandwiched in a state where the U shape lies on its side between the foundation plate 42 and the pillar 51. Therefore, the outer side surface on the lower side of the shock absorbing body 38a is in contact with the foundation plate 42, and the outer side surface on the upper side is in contact with the pillar 51. By assembling the shock absorbing bodies 38a on both right and left sides of the bearing body 11a, the pillar 51 can be stably supported. To reduce a displacement caused by ordinary load fluctuations, the thickness of the shock absorbing body 38a is adjusted to obtain a necessary spring constant. At approximate both ends of the shock absorbing body 38a, circular holes 39 to which the bolt 54 is inserted are formed.
The four lag screws 55 are screwed in the bottom surface of the pillar 51, and the top surface of the bearing body 11a and that of the shock absorbing body 38a are in surface contact with the end surface of the lag screw 55. Therefore, the load acting between the fastening device and the pillar 51 is distributed and transmitted into the pillar 51 via the entire lag screws 55. This avoids an otherwise concentrated load in a narrow region in the pillar 51, and may prevent a crack in the member.
a) and (b) show longitudinal sections of where the foundation plate 42 and the pillar 51 are fastened by using the fastening device of
When a shock load acts due to an earthquake or the like, horizontal loads acts on the pillar 51, and bending moments occur. When the bending moments become excessive, the shock absorbing bodies 38a are largely elastic-deformed. When the stresses exceed a limit, as shown in
a) to (c) and
In the first shape example of the bearing body 11 shown in
Also in a bearing body 11f of a second shape example of the whole fastening device shown in
After that, when the cross beam 59 is lifted, moved over the pillar 51, and gradually lowered while its position is adjusted, the pin 22 enters deep in a retaining groove 35, and the cross beam 59 is temporarily attached to the pillar 51 via the bearing body 11j. After that, when the bolt 54 is inserted in the shock absorbing body 38a and fastened, fixation of the cross beam 59 is completed. As an anchoring implement embedded in the side surface of the pillar 51, a deformed bar 58 is used not the lag screw 55. The deformed bar 58 is integrated with the pillar 51 by an adhesive.
Upon fastening the pillar 51 and the cross beam 59, the basic plate 12 is attached to the side surface of the pillar 51 in advance and, further, the shock absorbing bodies 38c are attached to both side surfaces of a lower part of the basic plate 12. The mounting plate 14 is attached to the end surface of the opposed cross beam 59 and, further, the shock absorbing bodies 38c are attached to both side surfaces of an upper part of the mounting plate 14. After that, when the cross beam 59 is lifted, moved over the pillar 51, and gradually lowered while its position is adjusted, the bottom surface of each of the shock absorbing bodies 38c comes into contact with the stopper 17 on the opposed side, and the cross beam 59 is temporarily attached to the pillar 51 via the shock absorbing bodies 38c and the stoppers 17. At this time, it is considered so that the pinholes 24 of the upper and lower arms 23 and 21 are concentrically aligned. When the pin 22 is inserted so as to penetrate the arms 21 and 23 and the clips 25 are attached, fixation of the cross beam 59 is completed.
Pressing pieces 66 and 67 can be attached to the side surfaces of the retainers 61 and 64 via bolts 68. In a state where the retainers 61 and 64 and the pressing pieces 66 and 67 are integrated, the stud bolts 38d can be retained. For this purpose, in the borders between the retainers 61 and 64 and the pressing pieces 66 and 67, internal screws 62 and 65 as female screws are used so that the stud bolts 38d can be screwed. Further, next to the internal screws 62 and 65, guide holes 63 in which the stud bolts 38d are inserted are formed.
The lower end of the stud bolt 38d is a left screw 81, and the upper end is a right screw 82. Consequently, the internal screw 62 of the retainer 61 and the pressing piece 66 on the lower side (the side of the basic plate 12) is a left screw and, on the other hand, the internal screw 65 of the retainer 64 and the pressing piece 67 on the upper side (the side of the mounting plate 14) is a right screw. At the time of assembling the stud bolt 38d, the stud bolt 38d is made to come into contact with the retainers 61 and 64 in a state where the pressing pieces 66 and 67 are detached and, then, the bolts 68 attach the pressing pieces 66 and 67. After that, as necessary, the stud bolt 38d is rotated to adjust the gap between the basic plate 12 and the mounting plate 14.
After the stud bolt 38d is plastic-deformed, for repair, as shown in
Pressing pieces 76 can be attached to the side surfaces of the retainers 71 via the bolts 68. In a state where the retainers 71 and the pressing pieces 76 are integrated, the shaft 38e can be retained. For this purpose, in the borders between the retainers 71 and the pressing pieces 76, restrainers 72 and guide holes 73 are formed so that the shafts 38e can be housed. The restrainer 72 is a part to which the stepped part 37 is fit and has the function of fixing the shaft 38e. The guide holes 73 have the function of regulating buckling of the shaft 38e also.
Even in the case where the shaft 38e is plastic-deformed by external force, the stepped part 37 is fit in the retainer 72. Consequently, the shaft 38e is not loosened from the basic plate 12 and the mounting plate 14, and the rigidity of the fastening device is maintained. At the time of replacing the shaft 38e that is plastic-deformed, it is sufficient to detach the pressing pieces 76 and pull the shaft 38e in the horizontal direction. Therefore, work can be done in a narrow space.
The entire mounting plate 14 is in contact with the bottom surface of the pillar 51. The lag screws 55 are screwed in the bottom surface of the pillar 51, the lower end surface of each of the lag screws 55 is in contact with the mounting plate 14, and the mounting plate 14 and the pillar 51 are firmly integrated. Further, the axial rod 31 is attached to the center of the mounting plate 14 by welding. The end of the axial rod 31 has a semispherical shape. By making the end come into contact with the recessed face 30, a connecting section capable of transmitting downward load is constructed. Naturally, the axial rod 31 can freely swing in the recessed face 30. The connecting section in the diagram is the same as that shown in
The basic plate 12 and the mounting plate 14 are disposed so as to completely overlap each other. To the entire peripheries of both of the plates, plate-shaped shock absorbing bodies 38f are attached. The shock absorbing body 38f is obtained by finishing a steel plate in a predetermined shape. To assure deformability to the vertical load, parts each having a shape of the less than signor the like in the shock absorbing body 38f are cut out. When a shock load is applied, plastic deformation occurs to absorb the energy. The four shock absorbing bodies 38f have the same shape and are attached to the basic plate 12 and the mounting plate 14 by the bolts 54. Consequently, the circular holes 39 and bottom grooves 36 are formed in the shock absorbing bodies 38f, and the screw holes 16 are formed in the side surfaces of the basic plate 12 and the mounting plate 14.
At the time of actually fixing the pillar 51 to the foundation 41, the basic plate 12 is fixed to the top surface of the foundation 41, and the mounting plate 14 is attached to the bottom surface of the pillar 51. After that, the four shock absorbing bodies 38f are fixed to the side surfaces of the mounting plate 14 by the bolts 54. Subsequently, to some of the screw holes 16 provided in the side surfaces of the basic plate 12, which are paired with the bottom grooves 36 in the shock absorbing bodies 38f, the bolts 54 are inserted in advance. The bolts 54 should not to be completely fastened. Between the basic plate 12 and the head of the bolt 54, a space for inserting the bottom groove 36 is assured. In such a manner, at the time of fixing the pillar 51 to the foundation 41, the pillar 51 can be temporarily put using the bottom grooves 36. After that, when the bolts 54 are inserted in the remaining circular holes 39, fixation of the pillar 51 is completed. At the time point when the pillar 51 is temporarily positioned, the axial rod 31 is in contact with the recessed face 30. Consequently, the entire load of the pillar 51 is not applied to the bottom grooves 36.
Although all of the connecting sections in
Number | Date | Country | Kind |
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2010-031651 | Feb 2010 | JP | national |
2010-209581 | Sep 2010 | JP | national |
2010-237295 | Oct 2010 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2011/053108 | 2/11/2011 | WO | 00 | 8/10/2012 |