Description

DEVICE FOR FIXING OBJECTS TO CEILING

Technical Field

[1] The present invention relates to a device for fixing objects to a ceiling, and more particularly to a device for fixing objects to a ceiling that is capable of conveniently mounting various objects to a supporting member protruding from a structure. Background Art

[2] In general, a building is equipped with a so-called access ceiling. The access ceiling has a structure that empty space is formed to be accessed, in which pipes, wires, cables, ducts, and the like are installed, and a finishing material like a panel is installed to shield the space. When constructing the access ceiling, in order to mount various objects, such as section steel bars, beams, carrying channels, pipes, wires, cables, and the like, to a structure, many kinds of devices for fixing the objects to the ceiling are used.

[3] Fig. 1 shows the constitution of a conventional device for fixing objects to a ceiling.

Referring to Fig. 1, foundation bolts 10 are fixed to a structure 2 constituting a ceiling of a building. The foundation bolts 10 are arranged apart from each other at a predetermined distance. Hangers 20 are mounted to the respective foundation bolts 10 by first nuts 12 and second nuts 14 being coupled to the foundation bolts 10. Each of the hangers 20 is formed with a hole 22, through which the corresponding foundation bolt 10 is inserted, at an upper portion, and includes an U-shaped holding portion 24, which has an opening 26, at a lower portion. A section steel bar 6 (an example of an object 4) passes through the opening 26 of the holding portion 24 of the hanger 20, so that a portion of the section steel bar 6 is supported by the hanger 20. A pin 30 is inserted through the upper portion of the holding portion 24 so as to prevent the separation of the section steel bar 6 by blocking the opening 26. Disclosure of Invention

Technical Problem

[4] In the above conventional device for fixing objects to a ceiling, the first nut 12 is first coupled to the foundation bolt 10, and the foundation bolt 10 is inserted through the hole 22 of the hanger 20. Then, the second nut 14 is coupled to the foundation bolt 10 to fixedly interpose the upper portion of the hanger 20 between the first nut 12 and the second nut 14. Therefore, the conventional device for fixing objects to a ceiling has problems that the installation process is very troublesome, time consuming, and complicated. Also, in order to prevent the separation of the pin 30 which is inserted through the holding portion 24 of the hanger 20, an end portion of the pin 30 should be

bent using a tool, such as pincers or a nipper, that makes the installation process more troublesome and complicated.

[5] Further, the first nut 12 and the second nut 14 are easily loosened from the foundation bolt 10 by vibration exerted on the foundation bolt 10 and the hanger 20. If the second nut 14 is loosened from the foundation bolt 10, the hanger 20 fixed to the foundation bolt 10 descends. When both end portions of the section steel bar 6 are supported by two hangers 20, if the second nut 14 is loosened and the hanger 20 descends, the section steel bar 6 becomes unbalanced. In a severe case, if the hanger 20 is separated from the foundation bolt 10, an accident where the section steel bar 6 falls down happens.

[6] Meanwhile, when a length of the foundation bolt 10 protruding from the structure 2 exceeds the design specification for the access ceiling, a front end portion of the foundation bolt 10 is cut off. At this time, a burr is generated at a cut surface of the foundation bolt 10, and the burr disables the first and second nuts 12 and 14 to be coupled to the foundation bolt 10. As a result, the burr should be removed by a grinding operation using a grinding machine or a file, which makes the installation process troublesome and complicated. Also when a screw thread of the foundation bolt 10 has scars or is deformed, the first and second nuts 12 and 14 cannot be coupled to the foundation bolt 10, which causes trouble in the installation process.

[7] Further, when mounting the hanger 20 to the ceiling of the building, a worker should get up on a ladder, a scaffold, or a lifter, and perform the operation of coupling the first and second nuts 12 and 14 using a tool such as a wrench. In this process, the worker is apt to carry many first and second nuts 12 and 14, hangers 20, and wrenches for efficient work. In addition, because the worker holds the first and second nuts 12 and 14 or the hanger 20 by one hand and holds the wrench by the other hand to couple the first and second nuts 12 and 14 to the foundation bolt 10, the worker working in a high place is considerably restricted in posture and actions. Accordingly, workability is low and safety accidents due to worker s awkward posture and actions frequently happen. Technical Solution

[8] The present invention has been made to solve the foregoing problems of the prior art, and it is an object of the present invention to provide a device for fixing objects to a ceiling that is capable of conveniently and promptly mounting various objects to a supporting member protruding from a structure.

[9] It is another object of the present invention to provide a device for fixing objects to a ceiling which is capable of securely mounting a hanger to a supporting member by the clamping force of a clamp, thereby increasing reliability and safety.

[10] It is a further object of the present invention to provide a device for fixing objects to a ceiling that is capable of mounting a hanger to a supporting member even when the supporting member has scars or burrs due to cutting, thereby increasing workability.

[11] It is yet another object of the present invention to provide a device for fixing objects to a ceiling which enables a worker working in a high place to have safe and optimum posture and actions without carrying additional tools for mounting a hanger to a supporting member.

Advantageous Effects

[12] As described above, according to the device for fixing objects to a ceiling of the present invention, since various objects can be mounted conveniently and promptly to the supporting member like a foundation bolt fixed to a structure like a ceiling, the required working time and a manpower decrease. Accordingly, workability increases and constructing costs reduce. Also, the hanger is securely mounted to the supporting member by a clamping force of the clamp, thereby increasing reliability and safety. The hanger can also be mounted to the supporting member even when the supporting member has scars or burrs due to cutting, thereby increasing workability. Further, a worker working in a high place is able to have safe and optimum posture and actions without carrying additional tools for mounting the hanger to the supporting member. Brief Description of the Drawings

[13] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[14] Fig. 1 is a perspective view illustrating a constitution of a conventional device for fixing objects to a ceiling;

[15] Fig. 2 is a perspective view illustrating a constitution of a device for fixing objects to a ceiling in accordance with a first embodiment of the present invention;

[16] Fig. 3 is an exploded perspective view illustrating a constitution of a device for fixing objects to a ceiling in accordance with a first embodiment of the present invention;

[17] Fig. 4 is a front view illustrating the state that a clamp is located at a second position in a device for fixing objects to a ceiling in accordance with a first embodiment of the present invention;

[18] Fig. 5 is a front view illustrating the state that a clamp is located at a first position in a device for fixing objects to a ceiling in accordance with a first embodiment of the present invention;

[19] Fig. 6 is a sectional view taken along line VI - VI in Fig. 4;

[20] Fig. 7 is a sectional view taken along line VII - VII in Fig. 5;

[21] Fig. 8 is a sectional view illustrating an operation that a clamp moves between a third position and a fourth position in a device for fixing objects to a ceiling in accordance with a first embodiment of the present invention; [22] Fig. 9 is a perspective view illustrating a constitution of a device for fixing objects to a ceiling in accordance with a second embodiment of the present invention; [23] Fig. 10 is an exploded perspective view illustrating a constitution of a device for fixing objects to a ceiling in accordance with a second embodiment of the present invention; [24] Fig. 11 is a front view illustrating a constitution of a device for fixing objects to a ceiling in accordance with a second embodiment of the present invention; [25] Fig. 12 is a sectional view illustrating the state that a clamp is located at a first position in a device for fixing objects to a ceiling in accordance with a second embodiment of the present invention; [26] Fig. 13 is a sectional view illustrating the state that a clamp is located at a second position in a device for fixing objects to a ceiling in accordance with a second embodiment of the present invention; [27] Fig. 14 is a perspective view illustrating a constitution of a device for fixing objects to a ceiling in accordance with a third embodiment of the present invention; [28] Fig. 15 is a perspective view illustrating a clamp of a device for fixing objects to a ceiling in accordance with a third embodiment of the present invention; [29] Fig. 16 is a sectional view illustrating the state that a clamp is located at a first position in a device for fixing objects to a ceiling in accordance with a third embodiment of the present invention; and [30] Fig. 17 is a sectional view illustrating the state that a clamp is located at a second position in a device for fixing objects to a ceiling in accordance with a third embodiment of the present invention.

Best Mode for Carrying Out the Invention [31] In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a device for fixing objects to a ceiling comprising: a supporting member which is protrudingly fixed to a structure; a hanger which includes a clamping portion having a first side plate, a second side plate arranged in parallel with the first side plate at a predetermined gap from the first side plate to accommodate the supporting member, and a connecting plate connecting the first side plate and the second side plate, the first side plate and the second side plate being respectively formed with a first operation hole and a second operation hole which are positioned opposite to each other, and a holding portion provided below the

clamping portion and having an opening for accommodating the objects; a clamp which is fitted through the first operation hole and the second operation hole and has a knob at one end to be in contact with an outer surface of the first side plate, the clamp moving between a first position for providing a clamping force to the clamping portion to fix the clamping portion to the supporting member accommodated between the first side plate and the second side plate and a second position for releasing the clamping force applied to the supporting member; and a spring which is provided at the other end of the clamp extending outward through the second operation hole of the second side plate and provides an elastic force for biasing the knob to be contactingly supported by the first side plate. Mode for the Invention

[32] Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings.

[33] Figs. 2 to 8 show a device for fixing objects to a ceiling in accordance with a first embodiment of the present invention. Referring to Figs. 2, 4 and 5, by using the device for fixing objects to a ceiling according to the first embodiment, objects 4, such as section steel bars, beams, carrying channels, pipes, wires, cables, and the like can be mounted to a structure 2, such as a ceiling or column of a building.

[34] Referring to Figs. 2 to 5, the device for fixing objects to a ceiling according to the first embodiment includes supporting members 110 which are protrudingly fixed to the structure 2. In this embodiment, the supporting members 110 are configured as foundation bolts 112 that protrudingly fixed to a ceiling of a building (an example of the structure 2). The foundation bolts 112 are arranged at a predetermined distance therebetween. Instead of the foundation bolts 112, the supporting members 110 may be configured as stud bolts, stud pins, support bars, bosses or protrusions protrudingly formed at the structure 2, or the like.

[35] Referring to Figs. 2 to 8, the device for fixing objects to a ceiling according to the first embodiment includes a hanger 120 which is mounted to each foundation bolt 112. The hanger 120 is made by press forming of a metal plate or die casting. The hanger 120 is formed with a C-shaped clamping portion 122 at an upper portion. The clamping portion 122 has a first side plate 126 and a second side plate 128 which are arranged in parallel with each other at a predetermined gap therebetween, so as to provide a space 124 in which the foundation bolt 112 is fitted. An end of the first side plate 126 is connected to an end of the second side plate 128 by a connecting plate 130. The first side plate 126 and the second side plate 128 are respectively formed with a first operation hole 132 and a second operation hole 134 at their central portions. The first operation hole 132 and the second operation hole 134 are positioned opposite to

each other. The connecting plate 130 has a curved shape and is formed with a female screw 136 on its inner surface to be coupled with the foundation bolt 112.

[36] As shown in Figs. 2 to 4, the hanger 120 is formed with a U-shaped holding portion 138 below the clamping portion 122. A section steel bar 6 (an example of the object 4) passes through the holding portion 138, so that a portion of the section steel bar 6 is supported by the holding portion 138. The holding portion 138 has an opening 140 at an upper portion. The holding portion 138 is formed with a bead 142 on its inner surface to reinforce strength and graduations 144 on its outer surface which are arranged in a vertical direction.

[37] Also, in order to prevent the separation of the section steel bar 6 from the holding portion 138, a snap lock 146 having an elastic force is formed integrally with an upper end of the holding portion 138. The snap lock 146 elastically blocks a portion of the opening 140. In other words, when fitting the section steel bar 6 in the holding portion 138 through the opening 140, the snap lock 146 comes into contact with the section steel bar 6 and is elastically deformed in an arrow A direction in Fig. 4 to widen the opening 140, so that the section steel bar 6 can be smoothly fitted in the holding portion 138. When the section steel bar 6 is completely fitted in the holding portion 138, the section steel bar 6 gets away from the snap lock 146, and the snap lock 146 is restored by its own elastic force to narrow the opening 140. Although it is illustrated and described that the holding portion 138 is formed in a U shape and has the opening 140 at the upper portion, this is not restricted thereto. The holding portion 138 may be formed in a C shape, which has the opening at any side portion.

[38] Referring again to Figs. 2 to 8, the device for fixing objects to a ceiling according to this embodiment includes a clamp 150 that provides a clamping force to the clamping portion 122 so that the clamping portion 122 is securely fixed to the foundation bolt 112 which is fitted in the space 124 of the clamping portion 122. The clamp 150 includes a main body 152 which has a circular cross-sectional shape. The main body 152 of the clamp 150 is movably inserted through the first and second operation holes 132 and 134 of the clamping portion 122.

[39] The main body 152 of the clamp 150 performs a rotational movement between a first position Pl and a second position P2 and performs a linear movement between a third position P3 and a fourth position P4. As shown in Fig. 7, when the main body 152 of the clamp 150 rotates to the first position Pl, the connecting plate 130 of the clamping portion 122 is forced toward the foundation bolt 112 to be fixed to the foundation bolt 112. For this, when the main body 152 of the clamp 150 is in the first position Pl, a gap between the inner surface of the connecting plate 130 of the clamping portion 122 and the main body 152 is smaller than an outer diameter of the foundation bolt 112. As shown in Fig. 6, the main body 152 of the clamp 150 is

formed with a semicircular-shaped recess 154 at its outer surface. When the main body 152 of the clamp 150 rotates to the second position P2, the foundation bolt 112 is received in the recess 154 of the main body 152, so that the clamping force by the pres- surization of the main body 152 is released. The clamp 150 has a knob 156 for the worker's manipulation, which is formed at an end of the main body 152. The knob 156 is in supportedly contact with the outer surface of the first side plate 126 of the clamping portion 122. The clamp 150 has a flange 158 which is formed at the other end of the main body 152 extending outward through the second operation hole 134 of the clamping portion 122.

[40] The movement of the clamp 150 is restricted by the operation of a position restriction mechanism 160. The position restriction mechanism 160 includes a first stopper 162 which is formed at the outer surface of the main body 152 of the clamp 150, and a guide recess 168 which is formed at the inner surface of the first operation hole 132 of the clamping portion 122 to guide the movement of the first stopper 162. The guide recess 168 is formed with a first stopping end 164 and a second stopping end 166 at both ends to stop the movement of the first stopper 162. The first stopping end 164 and the second stopping end 166 are arranged at an angle of 90 degrees therebetween. As shown in Figs. 5 and 7, when the main body 152 of the clamp 150 rotates to the first position Pl to force the foundation bolt 112, the first stopper 162 is caught by the first stopping end 164 and the movement stops. As shown in Figs. 4 and 6, when the main body 152 of the clamp 150 rotates to the second position P2 so that the foundation bolt 112 is received in the recess 154 of the clamp 150 to release the clamping force, the first stopper 162 is caught by the second stopping end 166 and the movement stops.

[41] The position restriction mechanism 160 further includes a second stopper 170 which is formed at the knob 156 of the clamp 150, and a first position determination hole 172 and a second position determination hole 174 which are formed in a peripheral direction around the first operation hole 132 at the first side plate 126 of the clamping portion 122, into which the second stopper 170 is fitted. The first position determination hole 172 and the second position determination hole 174 are arranged at an angle of 90 degrees therebetween. As shown in Figs. 5 and 7, when the main body 152 of the clamp 150 rotates to the first position Pl to force the foundation bolt 112, the second stopper 170 is caught by being fitted into the first position determination hole 172. As shown in Figs. 4 and 6, when the main body 152 of the clamp 150 rotates to the second position P2 so that the foundation bolt 112 is received in the recess 154 of the clamp 150 to release the clamping force, the second stopper 170 is caught by being fitted into the second position determination hole 174. At the third position P3, the second stopper 170 is fitted into either the first position determination hole 172 or the

second position determination hole 174. On the other hand, at the fourth position P4, the second stopper 170 is separated from the first position determination hole 172 or the second position determination hole 174 to allow the rotation of the clamp 150.

[42] Referring to Figs. 2, 3 and 6 to 8, the device for fixing objects to a ceiling according to the first embodiment further includes a spring 180 which provides an elastic force for biasing the clamp 150 from the fourth position P4 where the knob 156 of the clamp 150 is spaced apart from the first side plate 126 of the clamping portion 122 as shown by a real line in Fig. 8 to the third position P3 where the knob 156 of the clamp 150 is contactingly supported by the first side plate 126 as shown by an alternate long and two short dashes line in Fig. 8. The spring 180 is provided at the other end portion of the main body 152 of the clamp 150 which extends outward through the second operation hole 134 of the second side plate 128 of the clamping portion 122. The spring 180 is configured as a compression coil spring. One end of the spring 180 is supported by the outer surface of the second side plate 128 and the other end is supported by the flange 158, so that the separation from the main body 152 of the clamp 150 is prevented. The flange 158 may be configured as a snap ring or a split pin which is coupled to the other end of the main body 152 to prevent the separation of the spring 180. The spring 180 may be configured as a compression coil spring whose both ends are respectively caught by the second side plate 128 and the other end of the main body 152.

[43] Hereinafter, the operation of the device for fixing objects to a ceiling according to the first embodiment of the present invention structured as above will be described.

[44] Referring to Figs. 4 and 6, when the second stopper 170 is fitted into the second position determination hole 174, the clamp 150 is located at the second position P2, and the recess 154 of the main body 152 opposes the connecting plate 130 of the hanger 120. The worker inserts the foundation bolt 112 fixed to the structure 2 through the space 124 between the connecting plate 130 and the recess 154.

[45] The worker pulls the knob 156 of the clamp 150 in an arrow B direction in Fig. 8 to move the clamp 150 from the third position P3 to the fourth position P4. When the clamp 150 is located at the fourth position P4 as shown by a real line in Fig. 8, the second stopper 170 is separated from the second position determination hole 174, and the spring 180 disposed between the second side plate 128 and the flange 158 is compressed.

[46] Referring to Figs. 5, 7 and 8, when the worker manipulates the knob 156 to rotate the clamp 150 from the second position P2 to the first position Pl, the main body 152 rotates while being inserted through the first and second operation holes 132 and 134 and forces the outer surface of the foundation bolt 112. The forced foundation bolt 112 comes into close contact with the connecting plate 130 and is engaged with the female

screw 136 of the connecting plate 130, so that the hanger 120 is securely fixed to the foundation bolt 112. By the rotation of the clamp 150, the first stopper 162 moves along the guide recess 168, starting from the second stopping end 166, to the first stopping end 164 and is stopped by the first stopping end 164.

[47] When the worker releases the knob 156 in the state that the first stopper 162 is caught by the first stopping end 164, the compressed spring 180 is restored by its own elastic force, and the clamp 150 returns to the third position P3 from the fourth position P4. And, the second stopper 170 is fitted into the first position determination hole 172. Thereby, the process of mounting the hanger 120 to the foundation bolt 112 is completed. Through the aforesaid process, the worker can mount the hanger 120 to the foundation bolt 112 conveniently and promptly.

[48] As described above, since the hanger 120 is securely mounted to the foundation bolt 112 by the clamping force of the clamp 150, even when the foundation bolt 112 has scars or burrs due to cutting, it is possible to mount the hanger 120 to the foundation bolt 112. Accordingly, workability increases. And, when mounting the hanger 120 to the foundation bolt 112, the worker adjusts the lower end of the foundati on bolt 112 protruding downward from the clamping portion 122 to the graduations 144, so as to accurately locate the hanger 120 at a desired height.

[49] Referring to Figs. 2, 4 and 5, when the hanger 120 is completely mounted, the worker fits the section steel bar 6 through the opening 140 of the holding portion 138. The snap lock 146 is forced by the section steel bar 6 and is elastically deformed in the arrow A direction in Fig. 4 to widen the opening 140, so that the section steel bar 6 can be smoothly fitted in the holding portion 138. When the section steel bar 6 is completely fitted in the holding portion 138, the section steel bar 6 gets away from the snap lock 146, and the snap lock 146 is restored by its own elastic force to narrow the opening 140. Because the section steel bar 6 is caught by the snap lock 146, the section steel bar 6 is prevented from getting out of the opening 140.

[50] As such, since the hanger 120 can be mounted conveniently and promptly to the foundation bolt 112 protrudingly fixed to the structure 2, the mounting process can be achieved with a short working time and a less manpower, thereby increasing workability and reducing constructing costs. Because the hanger 120 is securely mounted to the foundation bolt 112 by the clamping force of the clamp 150, when the both ends of the section steel bar 6 are supported by two hangers 120, safety accidents due to separation of the hanger 120 and the fall of the section steel bar 6 are prevented and thus reliability and safety increase.

[51] Also, since the hanger 120 is securely fixed to the foundation bolt 112 by the clamping operation of the clamp 150 itself, the worker does not need to carry additional tools and can take a safe and optimum posture and actions when working in

a high place, thereby preventing the occurrence of safety accidents.

[52] Referring to Figs. 4, 5 and 8, when the worker moves the clamp 150 from the third position P3 to the fourth position P4, the second stopper 170 gets out of the first position determination hole 172 to permit the rotation of the clamp 150. When the worker rotates the clamp 150 from the first position Pl to the second position P2, the first stopper 162 moves along the guide recess 168, starting from the first stopping end 164, to the second stopping end 166 and is stopped by the second stopping end 166. At this time, the recess 154 of the clamp 150 opposes the connecting plate 130, and the clamping force exerted by the clamp 150 is released. Accordingly, the worker can demount the hanger 120 from the foundation bolt 112 conveniently and promptly.

[53] Figs. 9 to 13 show a device for fixing objects to a ceiling in accordance with a second embodiment of the present invention. Referring to Figs. 9 to 11, the device for fixing objects to a ceiling according to the second embodiment includes a foundation bolt 212, a hanger 220, a position restriction mechanism 260, and a spring 280, similarly to the above first embodiment which includes the foundation bolt 112, the hanger 120, the position restriction mechanism 160, and the spring 180. The constitutio n and the operation of the foundation bolt 212, the hanger 220, the position restriction mechanism 260 and the spring 280 of the device for fixing objects to a ceiling according to the second embodiment will be described by referring to the constitution and the operation of the foundation bolt 112, the hanger 120, the position restriction mechanism 160, and the spring 180 of the device for fixing objects to a ceiling according to the first embodiment, and the detailed explanation thereof will be omitted.

[54] Referring to Figs. 9 to 13, the device for fixing objects to a ceiling according to the second embodiment includes a clamp 250 that provides a clamping force to a clamping portion 222 so that the clamping portion 222 is securely fixed to the foundation bolt 212 that is fitted in a space 224 of the clamping portion 222. The clamp 250 has a main body 252. The main body 252 is movably inserted through first and second operation holes 232 and 234 which are respectively formed at first and second side plates 226 and 228 of the clamping portion 222.

[55] The clamp 250 performs a rotational movement and a linear movement between the first position Pl and the second position P2 through the first and second operation holes 232 and 234. As shown in Figs. 11 and 12, the main body 252 of the clamp 250 is formed with an eccentric cam portion 254, so as to force the foundation bolt 212 to the inner surface of the clamping portion 222 when the main body 252 is located at the first position Pl. As shown in Fig. 13, when the main body 252 is in the second position P2, a gap between the inner surface of a connecting plate 230 of the clamping portion 222 and the main body 252 is larger than an outer diameter of the foundation bolt 212, so as to release the clamping force applied to the foundation bolt 212. The

clamp 250 has a knob 256 for the worker's manipulation that is formed at an end of the main body 252. The knob 256 is in supportedly contact with the outer surface of the first side plate 226 of the clamping portion 222. The clamp 250 has a flange 258, which is formed at the other end of the main body 252 extending outward through the second operation hole 234 of the second side plate 228, to support the spring 280.

[56] The operation of the device for fixing objects to a ceiling according to the second embodiment structured as above will now be described. When the clamp 250 is restricted to the second position P2, the worker inserts the foundation bolt 212 fixed to the structure 2 through the space 224 between the connecting plate 230 and the main body 252 of the clamp 250, and rotates the clamp 250 from the second position P2 to the first position Pl.

[57] Also, the eccentric cam portion 254 of the clamp 250 at the first position Pl forces the foundation bolt 212 to the inner surface of the connecting plate 230, and the forced foundation bolt 212 comes into close contact with the connecting plate 230 and is engaged with a female screw 236 of the connecting plate 230, so that the hanger 220 is securely fixed to the foundation bolt 212. Identically to the first embodiment, the device for fixing objects to a ceiling according to the second embodiment has an effect that the hanger 220 can be mounted to the foundation bolt 212 conveniently and promptly.

[58] Figs. 14 to 17 show a device for fixing objects to a ceiling in accordance with a third embodiment of the present invention. Referring to Fig. 14, the device for fixing objects to a ceiling according to the third embodiment includes a foundation bolt 312, a hanger 320, a clamp 350, and a spring 380.

[59] Referring to Figs. 14 to 17, the hanger 320 is formed with a C-shaped clamping portion 322. The clamping portion 322 has a first side plate 326 and a second side plate 328 which are arranged in parallel with each other at a predetermined gap therebetween, so as to provide a space 324 in which the foundation bolt 312 is fitted. An end of the first side plate 326 is connected to an end of the second side plate 328 by a connecting plate 330. The first side plate 326 and the second side plate 328 are respectively formed with a rectangular first operation hole 332 and a circular second operation hole 334 at their central portions. The first operation hole 332 and the second operation hole 334 are positioned opposite to each other. The hanger 320 is formed with a U-shaped holding portion 338 below the clamping portion 322. The holding portion 338 has an opening 340 through which the section steel bar 6 passes so that a portion of the section steel bar 6 is supported by the hanger 320.

[60] Also, the main body 352 of the clamp 350 is inserted through the first and second operation holes 332 and 334 of the hanger 320 such that the main body 352 can move linearly between the first position Pl and the second position P2. The main body 352 is

formed with a rectangular shaft portion 352a which is non-rotatably fitted through the rectangular first operation hole 332, and a circular shaft portion 352b that extends from the rectangular shaft portion 352a and is fitted through the circular second operation hole 334. When the clamp 350 is in the first position Pl, a gap between the rectangular shaft portion 352a and the inner surface of the connecting plate 330 of the clamping portion 322 is smaller than an outer diameter of the foundation bolt 312, so that the rectangular shaft portion 352a forces the foundation bolt 312 to the inner surface of the clamping portion 322. A screw thread 352c is formed at one side surface of the rectangular shaft portion 352a that is engaged with the foundation bolt 312 at the first position Pl. The circular shaft portion 352b is formed with a semicircular- shaped recess 354 at its outer surface. When the clamp 350 is in the second position P2, the foundation bolt 312 is received in the recess 354. The main body 352 of the clamp 350 is formed with a knob 356 and a flange 358 at both ends. The knob 356 is contactingly supported by the outer surface of the first side plate 326. It is depicted in Figs. 16 and 17 that the knob 356 is formed in a flange shape, however the shape of the knob 356 can be changed adequately for the worker to conveniently grasp the same.

[61] The device for fixing objects to a ceiling according to the third embodiment further includes a spring 380 which is provided at the other end portion of the main body 352 of the clamp 350 which extends outward through the second operation hole 334 of the second side plate 328. One end of the spring 380 is supported by the second side plate 328 and the other end is supported by the flange 358. The spring 380 is configured as a compression coil spring which provides an elastic force for biasing the knob 356 to the first side plate 326.

[62] The operation of the device for fixing objects to a ceiling according to the third embodiment structured as above will now be described.

[63] Referring to Fig. 16, when the clamp 350 is in the first position Pl, the knob 356 is supported by the outer surface of the first side plate 326. Because the gap between the inner surface of the connecting plate 330 and the main body 352 is smaller than the outer diameter of the foundation bolt 312, the foundation bolt 312 cannot be fitted through the hanger 320.

[64] The worker pushes the flange 358 of the clamp 350 extending outward through the second operation hole 334 of the second side plate 328 to move the clamp 350 from the first position Pl to the second position P2 as shown by an arrow C in Fig. 17. When the clamp 350 moves to the second position P2, the recess 354 of the main body 352 opposes the connecting plate 330, and the spring 380 is compressed.

[65] Then, as shown in Fig. 17, the worker fits the foundation bolt 312 fixed to the structure 2 through the space 324 between the connecting plate 330 and the recess 354. When the worker removes the force of pushing the flange 358 of the clamp 350, the

compressed spring 380 is restored by its own elastic force, and the clamp 350 returns to the first position Pl from the second position P2. In the process that the clamp 350 returns to the first position Pl from the second position P2, a portion of the foundation bolt 312 received in the recess 354 gets out of the recess 354.

[66] As shown in Fig. 16, when the knob 356 of the clamp 350 comes into contact with the first side plate 326, the movement of the clamp 350 is stopped. When the clamp 350 is located at the first position Pl, the rectangular shaft portion 352a of the main body 352 forces the foundation bolt 312, and the foundation bolt 312 is engaged with the screw thread 352c of the rectangular shaft portion 352a. The foundation bolt 312 forced by the rectangular shaft portion 352a of the main body 352 comes into close contact with the connecting plate 330 and is engaged with the female screw 336 of the connecting plate 330. Thereby, the process of mounting the hanger 320 to the foundation bolt 312 is completed. When the mounting process of the hanger 320 is completed, the worker fits the section steel bar 6 into the holding portion 338 through the opening 340. Accordingly, the worker can mount the hanger 320 to the foundation bolt 312 conveniently and promptly.

[67] As described above, since the device for fixing objects to a ceiling according to the third embodiment has features that the hanger 320 can be mounted to the foundation bolt 312 by the linear reciprocating movement of the clamp 350, the position determination mechanism 160 and 260 of the first and second embodiments is not needed in the third embodiment. Accordingly, the constitution of the device for fixing objects to a ceiling according to the third embodiment is relatively simple, and manufacturing costs reduce.

[68] Meanwhile, as shown in Fig. 17, when the worker moves the clamp 350 from the first position Pl to the second position P2, the recess 354 of the clamp 350 is located at the space 324 between the first side plate 326 and the second side plate 328. The foundation bolt 312 is received in the recess 354, and the clamping force of the clamp 350 is released. Accordingly, the worker can demount the hanger 320 from the foundation bolt 312 conveniently and promptly.

[69] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Industrial Applicability

[70] As apparent from the above description, the device for fixing objects to a ceiling according to the present invention can be mounted to a supporting member like a foundation bolt, which is fixed to a ceiling, with a less manpower. Accordingly, labor

costs and construction period reduce. Further, since the mounting process can be easily performed just with a present technical standard, industrial applicability is very high. Especially, the present invention has a considerable ripple effect on buoyantly growing construction industry and interior industry.