1. Field of the Invention
The present invention relates to a bead-weaving loom used to make a fabric (beaded fabric) in which a plurality of beads; are woven.
2. Description of the Related Art
Conventionally, various types of bead-weaving looms or beading looms are known. For instance, the beading loom disclosed in Japanese unexamined utility model publication No. H06-6464 includes a pair of side plates, a pair of thread bars connected to the side plates, and a pair of spiral springs (thread holding bars) arranged between the thread bars. Each spiral spring holds a plurality of warp threads as spaced apart from each other. By using a beading loom of this type, as shown in
Japanese unexamined utility model publication No. S52-39268 discloses a beading loom that is capable of changing the distance between a pair of thread holding bars. The beading loom disclosed in this publication includes a pair of frames connected slidably to each other via a seat plate. The paired thread holding bars are attached to the paired frames, respectively. The seat plate is provided with two left and right fastening screws. By tightening the two screws, the relative movement of the paired frames is prevented.
The present invention has been conceived under the above-described circumstances. It is therefore an object of the present invention to provide a beading loom that is improved in convenience.
According to a first aspect of the present invention, there is provided a beading loom comprising: a first side support structure and a second side support structure spaced apart from each other in a lateral direction; a first thread fixing shaft for fixing one end of each of a plurality of threads, the first thread fixing shaft being rotatably connected to the first side: support structure and the second side support structure; a second thread fixing shaft for fixing the other end of each of the threads, the second thread fixing shaft being spaced apart from the first thread fixing shaft in a longitudinal direction perpendicular to the lateral direction and rotatably connected to the first side support structure and the second side support structure; a first thread supporting shaft provided adjacent to the first thread fixing shaft to hold the threads as spaced apart from each other in the lateral direction, the first thread supporting shaft being positioned between the first thread fixing shaft and the second thread fixing shaft as viewed in a height direction perpendicular to both of the lateral direction and the longitudinal direction and rotatably connected to the first side support structure and the second side support structure; and a second thread supporting shaft provided adjacent to the second thread fixing shaft to hold the threads as spaced apart from each other in the lateral direction, the second thread supporting shaft being positioned between the first thread fixing shaft and the second thread fixing shaft as viewed in the height direction and rotatably connected to the first side support structure and the second side support structure. Each of the first and second thread supporting shafts includes a first and a second thread supporting portions elongated in the lateral direction. The first and the second thread supporting portions are provided at different positions in a circumferential direction of the thread supporting shaft. Each of the first and the second thread supporting portions includes a plurality of grooves arranged at a predetermined pitch in the lateral direction. The pitch of the grooves of the first thread supporting portion differs from the pitch of the grooves of the second thread supporting portion.
Preferably, in the first aspect, each of the grooves of the first thread supporting portion and the grooves of the second thread supporting portion has a V-shaped cross section.
Preferably, in the first aspect, each of the first and the second thread supporting shafts has a cylindrical outer circumferential surface. Each of the first and the second thread supporting portions of each of the thread supporting shafts projects radially outward from the outer circumferential surface of the thread supporting shaft.
Preferably, in the first aspect, each of the first and the second thread supporting portions of each of the thread supporting shafts is formed with a plurality of through-holes having a common axis extending in the lateral direction.
Preferably, in the first aspect, the beading loom further comprises a first thread hook bar to be removably attached to the first thread supporting shaft and a second thread book bar to be removably attached to the second thread supporting shaft.
Preferably, in the first aspect, the first thread hook bar is provided between the first thread supporting portion and the second thread supporting portion in the circumferential direction of the first thread supporting shaft.
Preferably, in the first aspect, the beading loom further comprises an operation mechanism provided at each of the first and the second thread supporting shafts. Each of the thread supporting shafts includes a first end and a second end spaced apart from each other. The operation mechanism of each of the thread supporting shafts includes a threaded shaft which is provided at the first end and which rotates with the thread supporting shaft, a first operational portion which is provided at the second end and which rotates with the thread supporting shaft, and a second operational portion including a threaded hole meshing with the threaded shaft. The first side support structure and the second side support structure are provided between the first operational portion and the second operational portion.
According to a second aspect of the present invention, there is provided a beading loom comprising: a first side plate and a second side plate spaced apart from each other in a lateral direction; a third side plate and a fourth side plate spaced apart from the first side plate and the second side plate, respectively, in a longitudinal direction perpendicular to the lateral direction; a first thread fixing shaft for fixing one end of each of a plurality of threads, the first thread fixing shaft being connected to the first side plate and the second side plate; a second thread fixing shaft for fixing the other end of each of the threads, the second thread fixing shaft being connected to the third side plate and the fourth side plate; a first thread supporting shaft for holding the threads as spaced apart from each other in the lateral direction, the first thread supporting shaft being connected to the first side plate and the second side plate at a position adjacent to the first thread fixing shaft; a second thread supporting shaft for holding the threads as spaced apart from each other in the lateral direction, the second thread supporting shaft being connected to the third side plate and the fourth side plate at a position adjacent to the second thread fixing shaft; a first connecting member connecting the first side plate and the third side plate to each other; a second connecting member connecting the second side plate and the fourth side plate to each other; and a length adjustment mechanism for changing the distance between the first thread supporting shaft and the second thread supporting shaft stepwise by a predetermined pitch.
Preferably, in the second aspect, the length adjustment mechanism includes a plurality of grooves arranged at a predetermined pitch in the longitudinal direction and a protrusion for fitting in the grooves.
Preferably, in the second aspect, the grooves are provided at the first connecting member and the protrusion is provided at the first side plate.
Preferably, in the second aspect, the grooves are provided at the first side plate and the protrusion is provided at the first connecting member.
Preferably, in the second aspect, the grooves are connected to each other in the longitudinal direction and each has a V-shaped cross section, and the protrusion have a V-shaped cross section corresponding to the V-shaped cross section of the grooves.
Preferably, in the second aspect, the length adjustment mechanism includes an elongated hole provided at the first side plate and elongated in the longitudinal direction, a threaded hole provided at the first connecting member and facing the elongated hole, and a clamp bolt to be screwed into the threaded hole via the elongated hole.
Preferably, in the second aspect, the protrusion is provided on the outer side of the first connecting member in the lateral direction. The inner side of the first side plate in the lateral direction is formed with a guide groove for receiving the first connecting member movably in the longitudinal direction. The grooves are formed at the bottom of the guide groove.
Preferably, in the second aspect, the elongated hole is formed so as to cross the grooves, and the threaded hole is formed at a position corresponding to the protrusion as viewed in the lateral direction.
Preferably, in the second aspect, the outer side of the first side plate in the lateral direction is provided with a plurality of marks at positions corresponding to the grooves.
Preferably, in the second aspect, the first connecting member is provided with an additional protrusion spaced apart from the protrusion in the longitudinal direction.
According to a third aspect of the present invention, there is provided a heading loom comprising: a first side support structure and a second side support structure spaced apart from each other in a lateral direction; a first thread fixing shaft for fixing one end of each of a plurality of threads, the first thread fixing shaft being rotatably connected to the first side support structure and the second side support structure; a second thread fixing shaft for fixing the other end of each of the threads, the second thread fixing shaft being spaced apart from the first thread fixing shaft in a longitudinal direction perpendicular to the lateral direction and rotatably connected to the first side support structure and the second side support structure; a first thread supporting shaft rotatably connected to the first side support structure and the second side support structure at a position adjacent to the first thread fixing shaft, the first thread supporting shaft being provided for holding the threads as spaced apart from each other in the lateral direction; a second thread supporting shaft rotatably connected to the first side support structure and the second side support structure at a position adjacent to the second thread fixing shaft, the second thread supporting shaft being provided for holding the threads as spaced apart from each other in the lateral direction; and a first operation mechanism provided at the first thread fixing shaft. The first operation mechanism includes a first threaded shaft, a first operational portion and a second operational portion. The first threaded shaft projects to the outside of the first side support structure and rotates with the first thread fixing shaft. The first operational portion is provided on the outside of the second side support structure and rotates with the first thread fixing shaft. The second operational portion includes a threaded hole meshing with the first threaded shaft.
The first operational mechanism may be provided at the second thread fixing shaft.
Preferably, in the third aspect, the first thread fixing shaft has a first shaft hole penetrating the shaft in the lateral direction. The first operational mechanism includes a first shaft member which is inserted in the first shaft hole and which rotates with the first thread fixing shaft. The first shaft member has a first end at which the first threaded shaft is provided and a second end at which the first operational portion is provided.
Preferably, in the third aspect, the first thread fixing shaft includes a first end positioned adjacent to the first side support structure and a second end positioned adjacent to the second side support structure. The second end of the first thread fixing shaft is formed with a shaft end that is polygonal in cross section. The second end of the first shaft member is formed with a shaft member end that is polygonal in cross section. The first operational portion includes two polygonal recesses in which the shaft end and the shaft member end are fitted, respectively. According to this arrangement, each of the first thread fixing shaft and the first shaft member is unrotatable relative to the first operational portion.
Preferably, in the third aspect, the beading loom further includes a second operational mechanism provided at the first thread supporting shaft. The second operation mechanism includes a second threaded shaft, a third operational portion and a fourth operational portion. The second threaded shaft projects to the outside of the first side support structure and rotates with the first thread supporting shaft. The third operational portion is provided on the outside of the second side support structure and rotates with the first thread supporting shaft. The fourth operational portion includes a threaded hole meshing with the second threaded shaft.
The second operational mechanism may be provided at the second thread supporting shaft.
Preferably, in the third aspect, the first thread supporting shaft has a second shaft hole penetrating the shaft in the lateral direction. The second operational mechanism includes a second shaft member which is inserted in the second shaft hole and which rotates with the first thread supporting shaft. The second shaft member has a first end at which the second threaded shaft is provided and a second end at which the third operational portion is provided.
Other features and advantages of the present invention will become more apparent from detailed description given below with reference to the accompanying drawings.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings.
The left front side plate 1C and the right front side plate 1D are spaced apart from each other by a predetermined distance in a lateral direction. The left back side plate 1A and the right back side plate 1B are spaced apart from the left front side plate 1C and the right front side plate 1D, respectively, in the longitudinal direction (perpendicular to the lateral direction) and spaced apart from each other by a predetermined distance in the lateral direction.
The thread fixing shaft 2B is used to fix one end of each of a plurality of warp threads. The opposite ends of the thread fixing shaft 2B in the axial direction (lateral direction) are connected to the two front side plates 1C and 1D, respectively. The thread fixing shaft 2A is used to fix the other end of each warp thread. The opposite ends of the thread fixing shaft 2A in the axial direction are connected to the two back side plates 1A and 1B, respectively. The two thread fixing shafts 2B and 2A are spaced apart from each other in the longitudinal direction.
The opposite ends of the thread supporting shaft 3B in the axial direction are connected to the two front side plates 1C, 1D at positions adjacent to the thread fixing shaft 2B. The opposite ends of the thread supporting shaft 3A in the axial direction are connected to the two back side plates 1A, 1B at positions adjacent to the thread fixing shaft 2A. The thread supporting shafts 3B and 3A are at positions higher than the thread fixing shafts 2B, 2A and between the thread fixing shafts 2B and 2A in the longitudinal direction.
The connecting member 4A connects the left front side plate 1C and the left back side plate 1A to each other. The connecting member 4B connects the right front side plate 1D and the right back side plate 1B to each other.
The structure of the thread fixing shaft 2A and the connecting structure of the thread fixing shaft 2A to the two back side plates 1A and 1B are described below.
As shown in
A shaft member 25 is inserted in the shaft hole 214 of the thread fixing shaft 2A. The shaft member 25 is in the form of a round bar provided with a threaded shaft 251 at its distal end. At the base end (left end in
As shown in
As shown in
The structure of the thread fixing shaft 2B and the connecting structure of the thread fixing shaft 2B to the two front side plates 1C and 1D are substantially the same as those of the thread fixing shaft 2A. However, in the thread fixing shaft 2B, the shaft end 213 extends to the outside from the right front side plate 1D, and the operational portion 26 is provided on the outside of the right front side plate 1D (see e.g.
The thread fixing shafts 2A and 2B having the above-described structure are made of e.g. a synthetic resin such as polyacetal resin. For instance, each of the thread fixing shafts 2A and 2B can be made by integrally bonding two members divided in the radial direction.
The operation mechanism 6 is a mechanism for rotating the thread fixing shafts 2A and 2B and includes the above-described shaft members 25 and the operational portions 26 and 27.
The structure of the thread supporting shaft 3A and the connecting structure of the thread supporting shaft 3A to the two back side plates 1A and 1B are described below.
As shown in
A shaft member 35 is inserted in the shaft hole 314 of the thread supporting shaft 3A. The shaft member 35 is in the form of a round bar provided with a threaded shaft 351 at its distal end. At the base end of the shaft member 35, an end portion 352 that is polygonal (e.g. hexagonal) in cross section is provided. An operational portion 36 is attached to the end portion 352. The operational portion 36 is on the outside of the left back side plate 1A. The operational portion 36 is formed with recesses 361 and 362. The recess 361 has a cross sectional shape corresponding to that of the end portion 352, and the end portion 352 is fitted in the recess 361. Thus, the operational portion 36 and the shaft member 35 are not rotatable relative to each other. In the recess 362 is fitted the shaft end 313. Thus, the operational portion 36 and the thread supporting shaft 3A are not rotatable relative to each other. As will be understood from these, the thread supporting shaft 3A, the shaft member 35 and the operational portion 36 are not rotatable relative to each other. Thus, when the operational portion 36 is rotated, the thread supporting shaft 3A and the shaft member 35 (threaded shaft 351) rotate together with the operational portion 36.
As shown in
The outer circumference of the thread supporting shaft 3A is provided with a plurality of (two or more) thread supporting portions for supporting warp threads at different positions in the circumferential direction of the thread supporting shaft 3A. Preferably, these thread supporting portions are equally spaced from each other in the circumferential direction of the thread supporting shaft 3A. In the illustrated example, two thread supporting portions 32 and 33 are provided on the thread supporting shaft 3A as equally spaced apart from each other in the circumferential direction (e.g. arranged on the opposite sides across the central axis of the shaft).
As shown in
As shown in
As shown in
As shown in
The structure of the thread supporting shaft 3B (thread supporting portions 32, 33, scale marks 324, 334, attachment holes 311 and so on) is substantially the same as that of the thread supporting shaft 3A. In the thread supporting shaft 3B, the shaft end 313 extends to the outside from the right front side plate 1D, and the operational portion 36 is provided on the outside of the right front side plate 1D. The operational portion 37 having a threaded hole 301 meshing with the threaded shaft 351 is provided on the outside of the left front side plate 1C.
The thread supporting shafts 3A and 3B having the above-described structure are made of e.g. a synthetic resin such as polyacetal resin. For instance, each of the thread supporting shafts 3A and 3B can be made by integrally bonding two members divided in the radial direction.
The operation mechanism 7 is a mechanism for rotating the thread supporting shafts 3A and 3B and includes the above-described shaft members 35 and the operational portions 36 and 37.
The connecting structure that connects the connecting member 4A to the left back side plate 1A and the left front side plate 1C, and the connecting structure that connects the connecting member 4B to the right back side plate 1B and the right front side plate 1D are described below. Note that the connecting structure that connects the connecting member 4A to the left front side plate 1C and the connecting structure that connects the connecting member 4B to the right back side plate 1B and the right front side plate 1D are the same as the connecting structure that connects the connecting member 4A to the left back side plate 1A.
As shown in
As shown in
As shown in
As shown in
As shown in
In the above-described structure, when the clamp bolt 43 is loosened, the connecting member 4A moves inward in the lateral direction relative to the left back side plate 1A. As shown in
On the other hand, when the clamp bolt 43 is tightened, the protrusion 411 fits into the groove 14, so that movement of the connecting member 4A relative to the left back side plate 1A is inhibited. Since the grooves 14 are aligned at the predetermined pitch P3 in the longitudinal direction, by fitting the protrusion 411 into each groove 14, the position of the connecting member 4A relative to the left back side plate 1A can be changed stepwise by the pitch P3. Accordingly, as will be understood from
Similarly to the left back side plate 1A, each of the left front side plate 1C, the right back side plate 1B and the right front side plate 1D is provided with the guide groove 13, grooves 14, the elongated hole 15 and marks 16.
As shown in
Similarly to the connecting member 4A, the connecting member 4B includes the protrusions 411, threaded hole 412 and the hole 413.
As will be understood from the above-described structure, the positions of the two connecting members 4A, 4B relative to the two back side plates 1A, 1B can be changed stepwise by the pitch P3. Also, the positions of the two connecting members 4A, 4B relative to the two front side plates 1C, 1D can be changed stepwise by the pitch P3. That is, the length from the rear ends of the two front side plates 1C, 1D to the frond ends of the two back side plates 1A, 1B can be adjusted stepwise.
The protrusions 411 and the threaded hole 412 provided in each connecting member 4A, 4B and the grooves 14 and the elongated hole 15 provided in each side plate 1A, 1B, 1C, 1D constitute the length adjustment mechanism 5.
An example of beading operation using the beading loom A is described below with reference to
First, thread hook bars 34 are attached to the attachment holes 341 of the thread supporting shafts 3B and 3A. In the example shown in
Then, one end of a thread is fastened to e.g. the right thread hook bar 34 of the thread supporting shaft 3B. Then, the thread is fitted in one groove 322 (“first groove”) of each thread supporting shaft 3B, 3A while being longitudinally extended. Then, the thread is hooked around the right thread hook bar 34 of the thread supporting shaft 3A. Then, the thread is fitted into the groove 322 (“second groove”) on the immediate left of the first groove 322 while being extended. Then, the thread is hooked around the right thread hook bar 34 of the thread supporting shaft 3B. Then, the thread is fitted into the groove 322 on the immediate left of the second groove while being extended. After this operation is repeated a predetermined number of times with respect to the right thread hook bars 34 of the thread supporting shaft 3B and 3A, the same operation is performed with respect to the center thread hook bars 34 and the left hook bars 34. Finally, the terminal of the warp thread T1 is fastened to e.g. the left thread hook bar 34 of the thread supporting shaft 3A. In this way, as shown in
Then as shown in
Then, a weft thread on which a plurality of beads are strung is woven in the warp threads. Specifically, as shown in
By repeating this operation, a beaded fabric having a predetermined length in the direction in which the warp threads T1 extend (longitudinal direction) is made.
Then, after the stopper 35 is pulled out of the through-holes 323, the warp threads T1 are detached from the thread hook bars 34 by slightly turning the thread supporting shafts 3B and 3A. In this way, the beaded fabric is detached from the beading loom A. Then, by pulling the opposite ends of the warp threads T1, slack (e.g. the potions that have been hooked around the thread hook bars) is removed, whereby the work is completed.
The operation to make a relatively long beaded fabric is described below with reference to
First respective first ends of a plurality of warp threads T1 are fastened to the thread fixing shaft 2B. Specifically, each warp thread T1 is placed to bridge between the paired recesses 215 of the thread fixing shaft 2B, and in this state, a thread fixing member 29 is attached to the thread fixing shaft 2B. As shown in
Then, as shown in
Then, weaving of a weft thread on which beads are strung is performed. This weaving operation is performed similarly to the weaving described with reference to
Advantages of the beading loom A are described below.
In the beading loom A, each of the thread supporting shafts 3B and 3A is formed with a plurality of thread supporting portions 32 and 33 at different positions in the circumferential direction. The thread supporting portion 32 has a plurality of grooves 322 arranged at a predetermined pitch P1 in the axial direction, whereas the thread supporting portion 33 has a plurality of grooves 332 arranged at a predetermined pitch P2 in the axial direction. The pitch P1 of the grooves 322 and the pitch P2 of the grooves 332 differ from each other, and the pitch P1 is smaller than the pitch P2 According to this arrangement, to make a beaded fabric, the grooves 322 or the grooves 332 that have the pitch corresponding to the length of the beads B can be appropriately selected for use.
When relatively short beads B are used, as described with reference to
The grooves 322 and 332 having different pitches P1 and P2 are provided at each of the thread supporting shafts 3B and 3A. By appropriately rotating the thread supporting shafts 3B and 3A, switching between the grooves 322 and the grooves 332 can be easily performed.
Each of the grooves 322, 332 is V-shaped in cross section. Thus, as shown in
The thread supporting portions 32 and 33 project radially outward from the outer circumferential surfaces 310 of the thread supporting shafts 3B and 1A. According to this arrangement, by using the thread supporting portions 32 (33) as arranged on the upper side of the thread supporting shafts 3B and 3A, the warp threads T1 fitted in the grooves 322 (332) are prevented from coming into contact with the outer circumferential surfaces 310 of the thread supporting shafts 3B and 3A. As a result, the warp threads T1 are held at the bottom of the grooves 322 (332) so as not to move to the sides.
As described with reference to
As shown in
The thread hook bars 34 can be removably attached to either of the two regions positioned between the two thread supporting portions 32 and 33 (see the attachment holes 341 shown in
In this embodiment, the operation mechanisms 7 for rotating the thread supporting shafts 3A and 3B are provided. As described with reference to e.g.
According to the beading loom A of this embodiment, the length from the rear ends of the two front side plates 1C and 1D to the front ends of the two back side plates 1A and 1B (and hence, the distance between the thread supporting shaft 3B and the thread supporting shaft 3A) can be adjusted stepwise by the predetermined pitch P3 by the length adjustment mechanism 5. With this arrangement, the distance between the thread supporting shaft 3B and the thread supporting shaft 3A can be easily adjusted so as to be equal on the opposite sides in the lateral direction. As a result, uniform tension is applied to the warp threads T1 supported in parallel to each other by the thread supporting shafts 3B and 3A. This enhances the quality of the beaded fabric.
When a plurality of beaded fabrics which differ from each other in overall length are to be made, the length between the thread supporting shafts 3B and 3A can be adjusted stepwise by the pitch P3 depending on the overall length of each fabric.
The stepwise length adjustment can be performed by fitting each protrusion 411 into a selected one of the grooves 14 aligned at the predetermined pitch P3 in the longitudinal direction. According to this arrangement, the stepwise change of the positions of the connecting members 4A and 4B relative to the two back side plates 1A and 1B (two front side plates 1C and 1D) can be performed properly.
The grooves 14 formed in the two back side plates 1A and 1B (two front side plates 1C and 1D) are V-shaped in cross section and connected to each other in the longitudinal direction. Each of the protrusions 411 formed in the connecting members 4A and 4B has a V-shaped cross section to be fitted to (e.g. to come into close contact with) the grooves 14. According to this arrangement, even when the protrusion 411 is at first slightly deviated in the longitudinal direction from the groove 14 to be fitted, the two members are properly guided in the fitting process and finally fitted to each other at a proper position.
The operation to fit the protrusion 411 into the groove 14 is performed by screwing the clamp bolt 43 into the threaded hole 412 facing the elongated hole 15 (see
The elongated hole 15 is provided in the region were a plurality of grooves 14 are formed, and the threaded hole 412 is provided in the region where the protrusion 411 is formed. With this arrangement, in tightening the clamp bolt 43, the axial force of the screw portion acts efficiently due to the fitting of the protrusion 411 and the groove 14. This arrangement is advantageous for reliably fitting the protrusion 411 and the groove 14 to each other.
The outer sides of the two back side plates 1A and 1B (two front side plates 1C and 1D) in the lateral direction are provided with marks 16 at positions corresponding to the grooves 14. When the clamp bolt 43 is aligned with one of the marks 16, the corresponding groove 11 and the protrusion 411 face each other. Thus, the stepwise length adjustment can be performed easily.
The beading loom A of this embodiment includes the operation mechanism 6 for rotating the thread fixing shafts 2A and 2B. As described with reference to e.g.
The threaded shaft 251 is provided at one end of the shaft member 25. At the other end of the shaft member 25 is provided the operational portion 26. The shaft member 25 is received in the shaft hole 214 of the thread fixing shaft 2A (2B) and rotates with the thread fixing shaft 2A (2B). That is, the shaft member 25 is unrotatable relative to the thread fixing shaft 2A (2B). As will be understood from e.g.
As described with reference to e.g.
The beading loom A of this embodiment is provided with the operation mechanism 7 for rotating the thread supporting shafts 3A and 3B. As described with reference to e.g.
The threaded shaft 351 is provided at one end of the shaft member 35. At the other end of the shaft member 35 is provided the operational portion 36. The shaft member 35 is received in the shaft hole 314 of the thread supporting shaft 3A (3B) and rotates with the thread supporting shaft 3A (3B). As will be understood from
As described with reference to e.g.
Though the present invention has been described based on an embodiment, the present invention is not limited to the embodiment and can be varied in various ways without departing from the spirit of the invention.
For instance, while the grooves 14 and the protrusions 411 are V-shaped in cross section in the embodiment, the present invention is not limited to this, and any shape may be employed as long as the protrusions 411 are fitted in the grooves 14. For instance, the grooves 14 and protrusions 411 may have curved surfaces such as spherical surfaces. In the embodiment, grooves 14 are provided in the side plates 1A-1D, while protrusions 411 are provided in the connecting members 4A, 4B. The present invention is not limited to this, and the grooves 14 may be provided in the connecting members 4A, 4B, whereas the protrusions 411 may be provided in the side plates 1A-1D.
Number | Date | Country | Kind |
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2012-273292 | Dec 2012 | JP | national |
2012-273293 | Dec 2012 | JP | national |
2012-273294 | Dec 2012 | JP | national |