JP2000037211A - Connecting structure of band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make connecting an outer piece and an intermediate piece and adjusting a band length easier and prevent a spring bar from being lost by equipping a holding part to hold the spring bar onto the intermediate piece to prevent the spring bar from jumping out when the connection between the outer piece and the intermediate piece is released. SOLUTION: A connection between an inner piece 13 fit bridged to a cleat 7 of one outer piece 5 and the other outer piece 5a is completed by inserting a spring bar 4 into a space 11 of the intermediate piece 13. A cylindrical part 4b of the spring bar 4 is elastically held by a holding part 12 disposed on the intermediate piece 13 and the spring bar 4 is held at a prescribed position in the space 11 of the intermediate piece 13. The intermediate piece 13 in a condition a pin 4a of the spring bar 4 is inserted is inserted into a space 9 of the other outer piece 5a to insert the pin 4a of the spring bar 4 into through holes 6c, 6d of the other outer piece 5a to connect. Thus the spring bar 4 can be prevented from jumping out in connecting and releasing the outer piece and the intermediate piece since the spring bar 4 is elastically held by the holding part 12 disposed on the intermediate piece 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure for bands used for wristwatches and accessories.

[0002]

2. Description of the Related Art An example of a conventional band connection structure is shown in FIGS. A conventional band is generally configured by connecting pieces to each other using a pin called a hairpin, so that the length can be adjusted according to the thickness of the arm. FIG. 8 is an exploded perspective view showing a connected state of the raft-shaped piece bands, and FIG. 9 is a cross-sectional view of a portion where the pieces are connected by hairpins. As shown in FIG. 8, the watch band 20 is substantially configured by connecting a number of pieces 21c adjacent to each other with a connecting hairpin 27. And the other piece 21
Is located at one end of the frame body,
Arm 22 is provided at the other end thereof in the short direction of the band, and two second arms 23 are respectively provided so as to protrude in the longitudinal direction of the band.
2 has a through-hole 26 through which a hairpin 27 along the short side of the band can be inserted, and the second arm 23 has a through-hole 2 through which the hairpin 27 can be inserted through the short side of the band.
4 and 25 are formed respectively. Further, the through holes 24 and 25 are set so as to be located on the same line.

The first arm 22a of the one piece 21a and the second arm 23 of the other piece 21 are engaged with each other, and the second arm 23a is provided on both sides of the first arm 22a in the band short direction. Are made adjacent to each other. And
With the through holes 24 and 25 aligned with the through holes 26a,
The hairpin 27 is inserted from the through hole 25 on one end, and the insertion end of the hairpin 27 is inserted into the through hole 26a and the through hole 24 on the other end. The hairpin 27 has a bulged portion 27a having a spring property near the insertion end, and after the tip of the hairpin 27 is inserted into the through hole 24 at the other end, the rear end of the hairpin 27 is pushed in. Bulge 27
a is press-fitted into the through hole 25 on one end, and the hairpin 27 is fixed to the other piece 21. Thus, one piece 21a
The watch band 20 is constituted by alternately connecting the watch piece 20 and the other piece 21. For this prior art,
It is disclosed in Utility Model Publication (JP-A-63-140221).

However, in this prior art,
There was the following problem. When the hairpin 27 is used, the fixing force of the hairpin 27 changes due to a variation in the diameter of the hole processing because the through hole 25 of the other piece 21 and the bulging portion 27a of the hairpin formed in the hairpin 27 are fitted. I do. As a result, when the fixing force is too high, the assemblability of the band is deteriorated, and when the fixing force is too low, the band comes off during carrying. In addition, since the swelling portion 27a of the hairpin is constantly pressed, the spring property of the swelling portion 27a is reduced, and it is difficult to repeatedly use the swelling portion 27a.

[0005] In order to solve the above-mentioned problems, there has been increasing use of a spring bar instead of the hairpin 27. 10 and 11 show examples of a conventional band formed by connecting an outer piece and a middle piece with a spring bar. FIG.
Is a perspective view showing a connected state of the bands, and FIG. 11 is a sectional view of a portion where the pieces are connected by a spring bar.
11 shows an AA section, and FIG. 11B shows a BB section. This will be described below with reference to the drawings. The outer piece 5 made of two opposing muku materials is connected to a bar 7 provided on one side in the longitudinal direction of the band.
Through holes 6a and 6b into which the pins 4a at both ends of the spring bar 4 can be inserted are provided in the other side of the outer piece 5 in the transverse direction of the band. The through holes 6a and 6b are set so as to be located on the same line. Also, Nakakoma 3
A plate is formed by bending a single plate, and the ends of the plate are joined to form a flat ring shape, and a bar 7 of an outer piece is sandwiched on one of the inner sides, and a cylindrical portion 4b of a spring bar 4 is formed on the other. It has a space 8 that can be inserted.

For connecting the middle piece 3 to the other outer piece 5a by fitting it over the crosspiece 7 of one outer piece, the spring bar 4 is inserted into the space 8 of the middle piece 3. Next, the spring bar 4 is held while the pin 4a of the spring bar 4 is pushed in, the middle piece 3 is inserted into the space 9 of the other outer piece 5a, and the pin 4a of the spring bar is inserted into the through hole of the other outer piece 5a. 6
Insert into c and 6d and connect. As described above, the spring rod 4 is interposed between the through holes 6c and 6d of the other outer piece 5a and the space 8 of the middle piece 3 which is fitted over the crosspiece 7 of the one outer piece, thereby making the other outer piece 5a. 5a and the middle piece 3 are connected. In this way, the watch band 1 is formed by straddling the cross piece 7 of one outer piece and alternately performing the middle piece 3 and the other outer piece 5a.

[0007]

However, when a spring bar is used to connect the outer bridge and the middle bridge or between the bridge and the bridge, the pins at both ends of the spring bar inserted into the through holes of the middle bridge or the bridge are connected to each other. When inserted into the outer piece or through hole of the piece, there is a problem that the spring bar pops out and loses the spring bar. A similar problem occurs when the connection between the outer piece and the middle piece or between the piece and the piece is released. This is because, in the work of connecting the outer piece and the middle piece or the piece with the piece while the pin of the spring rod is pushed in, the through hole of the middle piece or the piece and the spring rod are not held in a loosely fitted state, so that the spring rod is not held. Is unstable. Therefore, there has been a problem that the work of assembling the band or the operation of adjusting the length of the band requires utmost care and skill, so that the workability is extremely poor.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, to easily connect an outer piece to a middle piece or a piece to a piece, to easily adjust the length of a band, and to project a spring bar. An object of the present invention is to provide a band connecting structure in which a spring bar is prevented from being lost and a pin of the spring bar does not come out of a hole of a bridge even when a watch is carried.

[0009]

In order to achieve the above-mentioned object, a band connecting structure according to the first aspect of the present invention is a band connecting structure for connecting an outer piece and a middle piece by a spring bar. In the connection structure, a holding portion for elastically holding the spring bar is provided on the middle block, and when the connection between the outer block and the middle block is released, the spring bar is prevented from jumping out. And

In order to achieve the above-mentioned object, the band connecting structure according to the second aspect of the present invention is the band connecting structure according to the first aspect, wherein the middle piece is formed by a sheet winding. In this case, the end portion of the plate winding is formed in a curl shape to serve as a holding portion for elastically holding the spring bar.

According to another aspect of the present invention, there is provided a band connecting structure according to the first aspect of the present invention, wherein: An inner winding member provided with a holding portion for elastically holding the spring bar is provided.

According to a fourth aspect of the present invention, there is provided a band connecting structure according to the first aspect of the present invention, wherein the middle piece is made of a rubber material. A protrusion (a dowel) is provided in a through hole in the short side direction of the band of the middle piece, and the protrusion (a dowel) is a holding portion for elastically holding the spring bar.

According to another aspect of the present invention, there is provided a band connecting structure for connecting a piece to a piece by a spring bar. Is provided with a holding portion for elastically holding the spring bar, and when the link between the pieces is released, the spring bars are prevented from jumping out.

According to another aspect of the present invention, there is provided a band connecting structure according to a sixth aspect of the present invention, wherein the piece is made of a rubber material. A protrusion (a dowel) is provided in a through hole in the band short direction of the piece, and the protrusion (a dowel) is a holding portion for elastically holding the spring bar.

According to another aspect of the present invention, there is provided a band connecting structure for connecting an outer piece to a middle piece or a piece to a piece by a spring bar. In the connecting structure of (1), a ring holding member having rubber or resin elasticity is attached to the outer periphery of the cylindrical portion of the spring bar, and the spring bar is pressed against the through hole in the band short direction of the piece. Wherein the spring is prevented from protruding from the through hole by the elasticity of the ring holding member when the connection between the pieces is released.

According to another aspect of the present invention, there is provided a band connecting structure according to a seventh aspect of the present invention. The band connecting structure according to claim 7, wherein a circumferential groove is provided on an outer periphery, and the ring holding member is mounted in the circumferential groove.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 and 2
The first embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 2 is a perspective view illustrating a band connecting structure according to the present embodiment, and FIG. 2 is a cross-sectional view illustrating the band connecting structure according to the present embodiment. The band connecting structure according to the present embodiment includes an outer piece made of a rubber material, a middle piece made of a sheet winding, and a spring bar connecting the outer piece and the middle piece. A holding portion for temporarily holding is provided. This will be described in detail with reference to the drawings. Since the outer piece and the spring bar are the same as conventional ones, the same reference numerals as those in FIG. 10 are used.

In the present embodiment, the intermediate piece 1 made of a sheet winding is used.
In step 3, a flat plate made of a stainless steel plate is bent by press working or the like to produce a flat annular body. On the other hand, the stainless steel outer piece 5 made of two opposing materials is integrated by a bar 7 provided on one side in the longitudinal direction of the band, and the pins 4a at both ends of the spring bar 4 are inserted into the other of the outer piece 5. Possible through holes 6a, 6b are provided at opposing positions in the short direction of the band. The outer piece 5 is manufactured by pressing and cutting after cutting to the width of the piece requiring a deformed line having a substantially elliptical cross section (in the widthwise direction of the band). Next, one end 13b of the plate winding is bent so as to form a flat annular body sandwiching the crosspiece 7 of the one outer piece 5 inside, and is fitted over the crosspiece 7 of the one outer piece 5. As a result, one outer piece 5 has a middle piece 13
Are linked. The other end 13a of the plate winding is further bent inward in a curl shape (arc shape) so as to form a space 11, thereby forming a spring rod holding portion 12. The space 11 has a cross section that is almost circular and has an inner diameter set slightly smaller than the outer shape of the cylindrical portion 4 b of the spring rod 4. Therefore, when the spring bar is inserted into the space 11 of the middle piece 13, the spring bar 4 is elastically held by the holding portion 12.

Next, a method of connecting the outer frame and the middle frame will be described. To connect the middle piece 13 fitted over the crosspiece 7 of one outer piece 5 to the other outer piece 5 a, the spring bar 4 is inserted into the space 11 of the middle piece 13. At this time, the cylindrical portion 4b of the spring bar 4 is
Are elastically held by the holding portion 12 provided in the first portion. Therefore, the spring bar 4 is held at a predetermined position in the space 11 of the middle piece 13. Next, with the pin 4a of the spring bar 4 pushed in, the middle piece 13 is inserted into the space 9 of the other outer piece 5a, and the pin 4a of the spring bar 4 is inserted into the through holes 6c and 6d of the other outer piece 5a. And connect.

As described above, according to the present embodiment, since the spring rod 4 is elastically held by the holding portion 12 provided on the middle piece 13, the work for connecting or releasing the outer piece and the middle piece is performed. It is possible to prevent the spring bar from jumping out inside and prevent the spring bar from being lost during work. Further, the band assembling work was facilitated, and the working efficiency was improved. In particular, as a result of using this connection structure for the adjustment piece that adjusts the length of the band, even if the connection between the outer piece and the middle piece is released, the spring bar is held in the through hole of the No more flying. In addition, the adjustment work becomes easy, and the wearer of the watch can easily adjust the length of the band.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view illustrating a band connection structure according to the present embodiment. The basic band connection structure is the same as that described in the first embodiment. The band connecting structure according to the present embodiment is configured such that an outer piece made of a rubber material and an inner piece made of a board are connected using a spring bar, and the spring bar is elastically held in the inner piece. This is a configuration in which a middle piece inner winding member provided with a holding portion is provided. Further, the structure of the inner winding member is similar to that of the inner member 13 in the first embodiment. The details will be described below with reference to the drawings. Since the outer piece and the spring bar are the same as those in the first embodiment, the same reference numerals as those in FIG. 1 are used.

The inner frame inner winding member 16 formed of a plate in this embodiment is manufactured by bending a flat plate made of a stainless steel plate by pressing or the like to form a flat annular body (plate winding). At this time, one end 16b of the plate winding is bent so as to form a flat plate winding sandwiching the crosspiece 7 of the one outer piece 5 inside, and is fitted over the crosspiece 7 of the one outer piece 5. As a result, the inner frame inner winding member 16 is connected to one outer frame 5. Also,
The other end 16a of the plate winding is further curled (arc-shaped) inward to form a space 11a to form a spring rod holding portion 12a. The space 11 a has a cross section that is almost circular and has an inner diameter set slightly smaller than the outer shape of the cylindrical portion 4 b of the spring rod 4. For this reason, when the spring bar 4 is inserted into the space 11a of the inner winding member 16, the spring bar 4 is elastically held by the holding portion 12a.

Further, the center piece 18 is a sheet winding formed by bending a flat plate made of a stainless steel plate by press working or the like. The both ends 18a and 18b of the sheet winding are joined to form a flat ring shape. The above-mentioned intermediate piece inner winding member 16
Is arranged. The connection between the outer frame and the middle piece in this embodiment is the same as in the first embodiment. The spring bar 4 is inserted into the space 11a of the inner frame inner winding member 16, and the spring bar 4 is moved to a predetermined position by the holding portion 12a. , And the pin 4a of the spring bar is inserted and connected to a through hole (not shown) of the other outer piece 5a. In addition, the effect of the present embodiment is the same as that of the first embodiment. However, since the gap between the both ends of the plate winding is joined in a very small state, the appearance of the first embodiment is visually reduced. Better than if.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIGS. The band connection structure in the present embodiment is configured to connect a piece made of a rubber material to a piece using a spring bar, and to provide a holding portion for elastically holding the spring bar on the piece. is there. FIG. 4 is an exploded perspective view showing a connected state of the raft-shaped piece band in the present embodiment, and FIG. 5 is a cross-sectional view of a part where the pieces are connected by a spring bar in this embodiment.
5A shows an AA section, and FIG. 5B shows a BB section.
This will be described in detail with reference to the drawings.

The piece 31 in this embodiment is manufactured by pressing and cutting after cutting to the width of the piece (in the direction of the shorter side of the band) requiring a deformed line having a substantially rectangular cross section. Piece 3
A first arm 32 is positioned at one end of the frame main body at the center thereof, and two second arms 33 are separated from each other in the other end in the short direction of the band. The first arm portion 32 has a through hole 36 through which the cylindrical portion 4b of the spring bar 4 can be inserted along the short side direction of the band, and the second arm portion 33 Are formed with through-holes 34 and 35 through which the pin 4a of the spring bar 4 can be inserted in the widthwise direction of the band. The through holes 34 and 35 are set so as to be located on the same line. Further, the through-hole 3 of the first arm portion 32
6, two convex portions (dowels) 37 are formed, and this portion constitutes a holding portion for holding the spring bar 4. The size of the protrusion 37 is set such that the inner diameter of the portion where the protrusion 37 is formed in the through hole 36 is slightly smaller than the outer diameter of the cylindrical portion 4 b of the spring rod 4. As a result, when the spring bar 4 is inserted into the through-hole 36, the cylindrical portion 4 b of the spring bar 4 is compressed by the holding portion including the convex portion 37, and the spring bar 4 is elastically held at a predetermined position of the through-hole 36. You.

Next, a method of connecting pieces to each other will be described.
Through hole 36 provided in first arm portion 32 of one piece 31
The spring bar 4 is inserted into. At this time, the cylindrical portion 4b of the spring rod 4 is elastically held by the holding portion including the convex portion 37 provided in the through hole 36. Therefore, the spring bar 4 is held at a predetermined position in the through hole 36 of the one piece 31. Next, with the pin 4a of the spring bar 4 pushed in, the first piece 31
Arm 32 of the other piece and second arm 33 of the other piece 31a
are engaged with each other, and the second arm portions 33a are respectively adjacent to both sides of the first arm portion 32 in the width direction of the band. Then, the first arm 3 of one of the pieces 31
2 and the pin 4a of the spring bar 4 is inserted into the through hole 3 of the other outer piece 31a in a state where the through hole 36 provided in the second piece 31a and the through holes 34a and 35a provided in the second arm portion 33a of the other piece 31a are aligned.
4a and 35a to connect one piece 31 and the other piece 31a.

As described above, since the spring bar 4 is elastically held by the holding portion formed of the convex portion 37 provided on the bridge 31, the spring bar 4 is connected to the bridge or is released during the work such as release. Jumping out can be prevented. Thereby, it was possible to prevent the spring bar from being lost during the operation. Further, the work of assembling the band or the work of adjusting the length of the band becomes easy, and the working efficiency is improved. Note that, in the present embodiment, an example has been described in which the protrusions are provided at two locations as the holding portions provided on the piece, but the same effect can be obtained by providing the projections at one location or at three or more locations. However, in consideration of the stability and economy of the held spring bar, it is preferable to install the spring bar at two locations.

In the same manner as in the above embodiment, a band consisting of an outer frame made of a chrysanthemum and a middle piece made of a chrysanthemum is provided with a convex portion in a through hole of the middle piece, and the spring bar is elastically held by this convex portion. Needless to say, the structure can be implemented.

(Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to FIGS. The connection structure of the band according to the present embodiment is basically the same as that described in the third embodiment, and is configured such that a piece made of Muku material and a piece are connected using a spring bar. A ring holding member having elasticity for holding the spring bar is mounted on the outer periphery of the spring bar. That is, while the holding member is provided inside the through hole of the bridge in the third embodiment, a ring holding member is provided on the spring rod in the present embodiment. FIG. 6A is an exploded perspective view showing a connected state of the raft-shaped piece bands in the present embodiment, and FIG.
FIG. 4 is an enlarged perspective view of a spring bar. FIG. 7 is a cross-sectional view of a part where pieces are connected by a spring bar in the present embodiment. This will be described in detail with reference to the drawings. The pieces are similar to those in the third embodiment, and therefore, the same reference numerals as in FIGS.

The spring rod 10 of the present embodiment is different from the spring rod of the prior art in that two circumferential grooves 10c are provided on the outer periphery of the cylindrical portion 10b, and the circumferential groove 10c is made of an elastic material made of rubber or resin. It is characterized in that the ring holding member 41 having On the other hand, the first arm portion 32 provided on the piece 31 has a through hole 40 through which the cylindrical portion 10b of the spring bar 10 can be inserted along the widthwise direction of the band, and the second arm portion 33 has the band hole. Pin 1 of spring bar 10 in short direction
Through holes 34 and 35 through which Oa can be inserted are formed respectively. The outer diameter of the ring holding member 41 attached to the circumferential groove 10c of the spring bar 10 is set slightly larger than the inner diameter of the through hole 40 provided in the arm portion 32 of the piece. As a result, when the spring bar 10 is inserted into the through hole 40, the ring holding member 41 is pressed against the inner wall of the through hole 40 to elastically hold the spring bar 10 at a predetermined position of the through hole 40. The method of linking the pieces is the same as in the third embodiment. Further, the same effect as that of the third embodiment can be obtained.

In the same manner as in the above embodiment, a band made of an outer piece made of a rubber material and a middle piece made of a rubber material is attached to an outer periphery of a spring bar, and a ring holding member 41 made of rubber or resin is attached. Needless to say, a structure can be implemented in which this spring bar is inserted into the through hole of the middle piece in the short direction of the band so as to press the ring holding member in pressure, and the spring bar is elastically held.

In the present embodiment, an example has been described in which the ring holding member is provided at two locations on the outer periphery of the spring bar. However, the same effect can be obtained by providing one or three or more ring holding members. However, in consideration of the stability and economy of the held spring bar, it is preferable to install the spring bar at two locations.

[0033]

As described above, according to the band connecting structure of the present invention, since the middle piece or the spring bar is elastically held by the piece, the outer piece and the middle piece, and the piece and the piece are connected to each other. The spring bar can be prevented from jumping out during operations such as connection or release. As a result, the work of assembling the band is facilitated and the working efficiency can be improved. Further, loss of the spring bar during operation can be prevented.

In particular, adjustment pieces for adjusting the length of the band
The effect is remarkable when this connection structure is used. That is, when the connection between the outer piece and the middle piece or between the piece and the piece is released, the spring bar is held in the through hole of the middle piece or the piece, so that the spring bar is prevented from being skipped, and the adjustment operation is facilitated. As a result, a general watch holder can easily adjust the length of the band. In addition, adjustment of the band length at a retail store or the like becomes easy, and quick response can be made according to the thickness of the customer's arm. Further, since the spring bar does not play in the through hole of the piece, the pin of the spring bar does not come off from the hole of the piece while the watch is being carried, and the connection between the pieces of the band is not released.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a band connecting structure according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a band connection structure according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a band connection structure according to a second embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a band connecting structure according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a band connection structure according to a third embodiment of the present invention.

FIG. 6 is an exploded perspective view showing a band connection structure according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view showing a band connection structure according to a fourth embodiment of the present invention.

FIG. 8 is an exploded perspective view illustrating a conventional band connection structure using a hairpin.

FIG. 9 is a cross-sectional view illustrating a conventional band connection structure using a hairpin.

FIG. 10 is an exploded perspective view showing a connection structure of a band using a spring bar in the related art.

FIG. 11 is a cross-sectional view illustrating a conventional band connection structure using a spring bar.

[Explanation of symbols]

 Reference Signs List 4 Spring bar 4a Spring bar pin 4b Spring bar cylinder 5, 5a Outer frame 6a, 6b, 6c, 6d Outer frame through hole 7 Outer frame beam 10 Spring bar 10a Spring bar pin 10b Spring bar cylinder 10c Spring Circumferential groove of rod 11 Space of middle piece 12 Holder 13 Middle piece 16 Inner piece of middle piece 31 Piece 37 Convex part 41 Ring holding member

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Toru Uehara 6-11-12 Honcho, Tanashi-shi, Tokyo Inside the Citizen Watch Co., Ltd. Tanashi Factory

Claims (8)

[Claims] In a band connecting structure for connecting an outer piece and a middle piece with a spring bar, a holding portion for elastically holding the spring bar is provided on the middle piece, and the outer piece and the middle piece are provided. Wherein the spring bar is prevented from jumping out when the connection with the band is released. 2. The band according to claim 1, wherein the middle piece is formed of a sheet winding, and an end of the sheet winding is formed into a curl shape to serve as a holding portion for elastically holding the spring bar. Connection structure. 3. The band connecting structure according to claim 1, wherein an inner winding member provided with a holding portion for elastically holding the spring bar is disposed inside the inner bridge. . 4. The middle piece is made of a rubber material, and a protrusion is provided in a through hole in the short direction of the band of the middle piece, and the protrusion serves as a holding portion for elastically holding the spring bar. The band connecting structure according to claim 1, wherein: 5. A band connecting structure for connecting a piece to a piece by a spring bar, wherein a holding portion for elastically holding the spring bar is provided on the piece, and the connection between the piece and the piece is released. Wherein the spring bar is prevented from protruding when the band is connected. 6. The piece is made of a rubber material, and a projection is provided in a through hole in the band short direction of the piece, and the projection is a holding portion for elastically holding the spring bar. The band connecting structure according to claim 5, wherein 7. A band connecting structure for connecting an outer piece and a middle piece or a piece and a piece by a spring bar, wherein a ring holding member having rubber or resin elasticity is attached to an outer periphery of a cylindrical portion of the spring bar, The spring rod is inserted into the through hole in the band short direction of the piece so as to press the ring holding member into contact with the piece, and when the connection between the piece and the piece is released, the elasticity of the ring holding member causes the ring to pass through the through hole. A band connecting structure wherein the spring bar is prevented from jumping out. 8. The band connecting structure according to claim 7, wherein a circumferential groove is provided on the outer periphery of the cylindrical portion of the spring bar, and the ring holding member is mounted in the circumferential groove.