KR101578855B1 - Spacer tower link structure that supports the connection to overhead power lines - Google Patents

Abstract

The present invention relates to a spacer connection structure of a steel tower for supporting a transmission line, more particularly, to a transmission tower for transmission in which both ends are connected to a steel tower spaced apart from each other by a predetermined distance, The present invention relates to a spacer connecting structure of a steel tower that supports a working transmission line that maintains a constant interval of transmission lines so as to prevent a safety accident caused by a power transmission line.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a span tower structure for supporting a transmission line,

The present invention relates to a spacer connection structure of a steel tower for supporting a transmission line, more particularly, to a transmission tower for transmission in which both ends are connected to a steel tower spaced apart from each other by a predetermined distance, The present invention relates to a spacer connecting structure of a steel tower that supports a working transmission line that maintains a constant interval of transmission lines so as to prevent a safety accident caused by a power transmission line.

Generally, the shape of a steel tower used as a support of a transmission line varies depending on the transmission power, voltage, and topography of the line, and may be 60 meters in height.

The main material is a steel material with an L-section in cross-section, and many horizontal cross-sections are square, and thus the foundation is also made of concrete at the apex of a square.

The pylon of the transmission line usually supports three phases, two lines, ie six wires.

Generally, the distance between the pylons is 20 to 30 m, and the minimum height from the surface of the pylon installed on the pylon is determined by the electric equipment technology, for example, 6 m for a 150,000 V line.

Generally, a strong structure is required when a railway crosses a wide river or a deep valley, because the span is long and therefore the tension of the wire increases.

Even the transmission line is small or there is a pillar built on a single foundation as a support for power lines or telephone lines.

The steel towers for transmission lines connect a plurality of transmission lines to each other. These transmission lines are installed under conditions where vibration or amplitude is likely to occur due to the influence of climatic influences such as wind or snow boiling due to the characteristic of being installed at high altitudes.

Especially, when strong winds are blown, the transmission lines are shaken up and down so that friction between the transmission lines may be intertwined. This causes a large safety accident such as short-circuit or short-circuit.

In order to solve such a problem, conventionally, a spherical weight, i.e., a weight, is installed at predetermined intervals of transmission lines to prevent the transmission line from shaking due to the influence of the climate.

However, it is obvious that the conventional technique described above can be expected to simplify the installation. However, as mentioned above, since the weights are individually suspended for each transmission line, there is a limit to effectively prevent the upside and downside of the transmission lines.

Accordingly, in recent years, an attempt has been made to prevent the contact phenomena between the transmission lines by using a space between the clamps connected to the transmission lines, the loops connected and held between the clamps, the insulation between the loops, and the plurality of vanes.

However, the conventional structure thus constructed is designed to receive a large wind resistance in the outer structure, causing severe shaking phenomenon and a structure of a relatively heavy load, which causes a change in the tension of the transmission line and causes a sagging of the transmission line.

In addition, although the upper and lower intervals of the power transmission lines can be maintained, it is difficult to maintain the horizontal spacing between the power transmission lines provided at the same height. When the wind swings occur, the gap between the power transmission lines can be maintained because the impact can not be absorbed. The effect of reducing the external force applied to the transmission line could not be expected.

In addition, related prior art is the registered patent No. 0861132 (2008.09.24).

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and it is an object of the present invention to provide a transmission line capable of maintaining vertical and horizontal spacing between transmission lines and capable of reducing an external force applied to transmission lines. A spacer connecting structure of a steel tower for supporting a working transmission line is provided.

In order to achieve the above object, the present invention provides a spacer for maintaining a spacing distance between transmission lines (1), the spacer being hexagonal and having a hollow inside, and each corner portion extending radially from the center A body 10 including a boss 11 provided with a sliding hole 12; A rod 21 which is coupled to the boss 11 so as to be pulled in and pulled out along the sliding hole 12 and a rod 21 which is screwed to the end of the rod 21 and has a larger diameter than the sliding hole 12 And a spring 26 which surrounds the outer circumferential surface of the rod 21 and has one side abutting against the lower end of the boss 11 and the other abutting against the upper end of the engaging member 25, A shock absorber unit (20) comprising; And a clamping unit 30 coupled to an upper end of the rod 21. The clamping unit 30 is formed to be able to support the transmission line 1 for a predetermined length and protrudes outward on one side, A lower member 35 having a plurality of first engaging portions 36 formed with an engaging hole 37 penetrating the upper and lower surfaces of the lower member 35 and a lower member 35 hinged to one side of the lower member 35 in a rotatable manner, And an upper member (31) having a second engaging portion (32) formed with a locking protrusion so as to be detachably coupled to the engaging hole (37) of the first engaging portion (36) Two guide grooves 13 extending downward along the longitudinal direction of the boss 11 from the upper end are provided on the inner surface of the boss 11 so as to guide the lifting direction of the boss 11, 21 are formed with guide projections 23 which move along the guide grooves 13, The clamping unit 30 includes an air passage hole 39 for communicating the inside and the outside with the upper member 31 and the lower member 35 so as to prevent moisture from being caught on the outer circumferential surface of the transmission line 1 to be coupled, And a groove (40) for providing a movement path through which the air introduced from the outside along the inner peripheral surface of the member (31) and the lower member (35) can move; The rod 21 further includes a length adjusting means 50. In order to install the length adjusting means 50, the rod 21 is formed in a hollow cylindrical shape, A pair of operating holes 52 are formed in a part of the length of the upper rod 21a so as to be diametrically opposed to each other and a lower portion of the lower portion of the operating rod 52 A plurality of height adjusting holes 56 are formed through the height adjusting portion 54 at regular intervals in the longitudinal direction, The upper rod 21a has a stepped portion to be fitted to the height adjusting portion 54. When the upper rod 21a is fitted into the height adjusting portion 54 which is the lower end of the upper rod 21a, 21b are provided with a plurality of holes corresponding to the height adjusting holes 56, A height adjusting member 60 is inserted into a height adjusting hole 56 of the upper rod 21a and the height adjusting member 60 is inserted into the height adjusting hole 56, The upper end of the fitting hole 62 is partially exposed to the outside through the height adjusting hole 56 and an upper spring SP1 is provided at a rear end opposite to the lower end of the fitting hole 62. [ The upper and lower ends orthogonal thereto are engaged with the inside of the height adjusting hole 56 to stop the fitting opening 62 from escaping to the outside, And a pushing knob (64) is screwed to the distal end face of the fitting opening (62), and the pushing knob (64) is screwed on the distal end face of the fitting opening A first extension 66a extending obliquely toward the center of the inner diameter of the upper rod 21a is provided at the lower end of the fitting hole 62, A second extending portion 66b extending in a vertical direction is formed at a lower end of the first extending portion 66a and a second extending portion 66b is formed at a lower end of the second extending portion 66b, And a third extending portion 66c extending obliquely in a direction opposite to the first extending portion 66c. The third extending portion 66c is formed at its end with a latching opening 68 extending in parallel with the fitting opening 62, A lower spring SP2 is engaged and fixed between the second extended portions 66b for the purpose of activating the operating member 62 and the stopper 68 and a position where the lower spring SP2 does not interfere with the lower spring SP2 A guide hole G is formed in the guide hole H so that the guide bar G is inserted into the guide hole G. The guide bar G is inserted into the second extended portion 66b, And the second extending portions (66b) are opposed to each other and are fixed while being offset from each other on the opposed surfaces of the pair of second extending portions (66b) facing each other. It provides.

According to the present invention, the space of the transmission line can be easily maintained at the upper, lower, left, and right intervals of the transmission line, and the external force can be reduced by the shock absorbing unit when the transmission line is shaken by the external force.

1 is a front view showing one embodiment of a transmission line spacer according to the present invention, Fig.
FIG. 2 is a partially cutaway perspective view showing the boss, the shock absorbing unit and the clamping unit of the embodiment of FIG. 1,
3 is a sectional view of the shock absorbing unit of the embodiment of FIG. 1,
4 is a cross-sectional view of the clamping unit of the embodiment of Fig.
5 is an exemplary partial cross-sectional view showing the rod length adjusting means of the embodiment of FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Before describing the present invention, the following specific structural or functional descriptions are merely illustrative for the purpose of describing an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention may be embodied in various forms, And should not be construed as limited to the embodiments described herein.

In addition, since the embodiments according to the concept of the present invention can make various changes and have various forms, specific embodiments are illustrated in the drawings and described in detail herein. However, it should be understood that the embodiments according to the concept of the present invention are not intended to limit the present invention to specific modes of operation, but include all modifications, equivalents and alternatives falling within the spirit and scope of the present invention.

The present invention uses the above-mentioned prior-art patent No. 0861132 as it is. Therefore, all of the features of the device configuration described below are those described in Japanese Patent No. 0861132. [

However, in order to achieve the object of the present invention, the present invention is characterized in that a part of the specific configuration is improved.

1, a spacer 100 according to the present invention includes a hexagonal body 10, a shock absorbing unit (not shown) which is movably installed in the body 10 and serves as a buffer for absorbing and reducing external vibrations And a clamping unit 30 installed at an upper end of the impact absorbing unit 20 and adapted to clamp the transmission line 1. [

The main body 10 is formed to have a hexagonal shape at its edges, and a through hole is formed through the upper and lower surfaces.

The through holes are hexagonal like the edges of the main body 10, and the six edges of the inner surface formed with through holes extend parallel to the edges of the outer peripheral surface of the main body 10, respectively.

Since the main body 10 is installed in the transmission line 1, it is preferable that the main body 10 is made of a material which is light and durable so as to prevent the transmission line 1 from being sagged by applying a high load to the transmission line 1.

The body 10 is also provided with bosses 11 at six corners. The boss 11 extends in a radial direction from the center of the main body 10 and has a sliding hole 12 extending in the radial direction.

The sliding hole 12 is formed to penetrate the lower surface from the upper surface of the boss 11 and has a diameter corresponding to the rod 21 of the impact absorbing unit 20 described later.

In addition, two guide grooves 13 extending along the longitudinal direction of the boss 11 are provided on the inner side surface of the boss 11 on which the sliding hole 12 is formed.

The guide groove 13 extends only to a position spaced apart from the lower end surface of the boss 11 by a predetermined length.

The impact absorbing unit 20 minimizes the influence of the external force on the other power transmission line 1 coupled to the other side of the main body 10 when the power transmission line 1 coupled to one side of the main body 10 is shaken by an external force A rod 21 slidably coupled to the sliding hole 12 of the boss 11; a coupling member 25 coupled to an end of the rod 21; And a spring 26 installed so as to surround it.

The rod 21 is provided with a clamping unit 30 at an upper portion thereof and a threaded portion 22 at a lower end thereof so that a coupling member 25 can be coupled thereto.

The rod 21 is inserted into the sliding hole 12. Since the rod 21 is formed in a cylindrical shape like the sliding hole 12 and has a diameter corresponding to the sliding hole 12, It is possible to move up and down along the longitudinal direction of the vehicle. On the side surface of the rod 21, there is provided a guide projection 23 which is protruded by a predetermined length from the outer circumferential surface of the rod 21 to the outside.

The rod 21 is coupled to the boss 11 such that the guide protrusion 23 can move along the guide groove 13 formed on the inner surface of the boss 11. [

When the rod 21 ascends and descends along the sliding hole 12 of the boss 11, the rod 21 rotates inside the boss 11, Is prevented. A hooking jaw 24 having a larger diameter than the sliding hole 12 of the boss 11 is provided at one side of the upper portion of the rod 21 so as to prevent the rod 21 from falling downward through the sliding hole 12 .

The coupling member 25 is coupled to the end of the rod 21 at the inside of the main body 10 and is screwed to the threaded portion 22 provided at the end of the rod 21.

The engaging member 25 is formed to have a larger diameter than the sliding hole 12 so as to prevent the rod 21 from being displaced upward from the boss 11 through the sliding hole 12 when the rod 21 is engaged with the rod 21. [ And the outer circumferential surface of the coupling member 25 is formed to be the same as a hexagonal nut so that the coupling member 25 and the rod 21 can be easily coupled and separated using a tool such as a spanner.

One end of the spring 26 is in contact with the lower end surface of the boss 11 and the other end of the spring 26 is in contact with the upper end surface of the coupling member 25, And is installed to surround the outer circumferential surface of the rod 21 from the lower side.

The rod 21 moves up and down a certain length along the sliding hole 12 of the boss 11 so that the power transmission line 1 is lifted up and down by the external force, To minimize the influence of the shaking of the other transmission line (1).

When the external force disappears, the rod (21) is returned to its original position by the spring (26).

The clamping unit 30 is for clamping the transmission line 1 to the main body 10 and includes an upper member 31 and a lower member 35 which are formed so as to surround the outer circumferential surface of the transmission line 1, .

The lower member 35 is connected to the upper end of the rod 21 and has a semicircular cross section which is drawn downward so as to cover a lower certain region of the transmission line 1, The length is extended accordingly.

A hinge hole through which the hinge shaft 38 can be inserted is provided at one side of the lower member 35 so as to be rotatably coupled with the upper member 31.

A plurality of first engaging portions 36 protruding outward from the edge of the lower member 35 at the other side of the lower member 35 and provided with an engagement hole 37 penetrating the upper and lower surfaces thereof are engaged with the lower member 35 And is spaced a certain distance along the longitudinal direction of the frame.

The upper member 31 is coupled to the lower member 35 to grasp the power transmission line 1 and has a hinge hole through which the hinge shaft 38 can be inserted, And is rotatably coupled to the lower member 35 by a hinge shaft 38 and has a second engaging portion 32 corresponding to the first engaging portion 36 at the other side edge thereof.

The upper member 31 has a semicircular cross-sectional shape drawn upward so as to cover a predetermined upper region of the transmission line 1. The upper member 31 has first and second engaging portions 36 and 32 after being coupled with the lower member 35 A hollow is formed inside the upper member 31 and the lower member 35 so that the transmission line 1 can be positioned.

The second engaging portion 32 is formed to have a size capable of passing through the engaging hole 37 of the first engaging portion 36. The first engaging portion 36 is formed at one side of the first engaging portion 36, A fixing jaw 33 is formed to prevent the first engaging portion 32 from being separated from the second engaging portion 32 when the second engaging portion 32 is engaged with the second engaging portion 32 through the engaging hole 37. [

The first engaging portion 36 is not separated from the second engaging portion 32 by the fixing jaw 33 unless the worker artificially applies an external force.

Further, a pressing protrusion 34 protruding downward is provided on the inner side surface of the upper member 31. When the upper member 31 and the lower member 35 are coupled so as to enclose the power transmission line 1, the pressure projection 34 presses the power transmission line The upper member 31 is pressed by the pressing protrusion 34 in the outward direction of the transmission line 1 because the pressing protrusion 34 is in contact with the outer peripheral surface of the transmission line 1 and the pressing protrusion 34 is protruded to the lower side of the upper member 31 by a predetermined length, do.

When the upper member 31 and the lower member 35 are coupled by the first and second engaging portions 36 and 32, the upper member 31 is urged outward by the urging member, 36 are more firmly fastened to the second engagement portion 32. [

The upper member 31 and the lower member 35 are provided with an air passage hole 39 and a groove 40 for preventing the outer circumferential surface of the power transmission line 1 from being wetted.

External air is easily introduced into the inside of the clamping unit 30 by the air passage holes 39 formed to pass through the upper and lower surfaces of the upper member 31 and the lower member 35, The air introduced into the inside of the clamping unit 30 by the plurality of grooves 40 extending along the longitudinal direction and along the direction orthogonal to the longitudinal direction on the inner surface of the lower member 35 It can easily flow.

Air circulation is smoothly performed on the outer circumferential surface of the power transmission line 1 by the air passage hole 39 and the groove 40 to prevent moisture from being caught on the outer circumferential surface of the power transmission line 1 and safety accidents Can be prevented.

In addition, as shown in FIG. 5, the present invention may further include a length adjusting means 50.

In other words, the length of the lower rod 21 of the latching jaw 24 is cut into a hollow body, that is, a cylindrical shape, And is divided into an upper rod 21a and a lower rod 21b separately.

At this time, a pair of operation holes (52) are formed peripherally around the length of the upper rod (21a) so as to oppose each other in the radial direction.

The lower portion of the operation hole 52 has a height adjusting portion 54 extending downward in a state of being thin with a step.

In addition, a plurality of height adjusting holes 56 are formed in the height adjusting portion 54 at regular intervals in the longitudinal direction.

In this case, the height adjusting holes 56 are formed to be opposed to each other in the radial direction of the height adjusting portion 54, like the operating holes 52.

The lower rod 21b has a stepped portion to be fitted into the height adjusting portion 54. When the lower rod 21b is fitted into the height adjusting portion 54 which is the lower end of the upper rod 21a, the outer circumferential surfaces thereof are aligned with each other.

In addition, a plurality of fitting holes 58 corresponding to the height adjusting holes 56 are formed in a part of the upper end of the lower rod 21b.

At this time, the fitting holes 58 are also formed in pairs facing each other in the radial direction like the height adjusting holes 56.

A height adjusting member 60 is fitted to the height adjusting hole 56 of the upper rod 21a.

The height adjusting member 60 includes an elongated fitting 62 which is fitted into the height adjusting hole 56.

When the upper spring SP1 is fitted to the rear end of the fitting hole 62, the tip is inserted into the height adjusting hole 56 and partially exposed to the outside, and the upper and lower ends orthogonal to the upper spring SP1 are adjusted And is engaged with the inner side of the hole 56 to stop the insertion port 62 from escaping to the outside.

At this time, the upper springs SP1 are hooked to the rear ends of a pair of fitting holes 62, which are diametrically opposed to each other, so as to elastically push the upper springs SP1.

In addition, the pushing knob 64 is screwed to the end surface of the fitting hole 62, that is, the end surface exposed through the height adjusting hole 56.

Since the pushing knob 64 has a structure in which the pushing knob 64 is removably assembled by screwing, the pushing knob 62 is assembled in a state in which the fitting opening 62 is first inserted.

This is to facilitate installation of the fitting 62 in a narrow space such as the inner diameter of the upper rod 21a.

A first extension 66a extending obliquely toward the center of the inner diameter of the upper rod 21a is formed at a lower end of the fitting hole 62. A lower end of the first extension 66a And a third extension 66c is formed at the lower end of the second extension 66b to extend in a direction opposite to the first extension 66a And a locking hole 68 extending parallel to the fitting hole 62 is formed at the end of the third extension 66c.

The reason why the first and third extensions 66a and 66c are inclinedly extended is that when the pushing knob 64 is pressed, the hooking hole 68 has sufficient strength and is inserted into any one of the height adjusting holes 56 This is to facilitate withdrawal.

That is, it is for the purpose of enhancing the durability of the stopper 68.

In addition, the stopper 68 is inserted into any one of the height adjusting holes 56 and formed to have a length twice as thick as the thickness of the upper rod 21a, Always be configured to remain exposed to the outside.

In addition, the pushing knob 64 must be formed longer than the length of the hook 68.

Thus, when the pushing knob 64 is pressed, the latching hole 68 can be easily inserted into the height adjusting hole 56, and if the pushing knob 64 is fully inserted into the height adjusting hole 56, It can move in the height direction.

Further, a lower spring SP2 is engaged and fixed between the second extension portions 66b for activating the operation source of the fitting opening 62 and the engagement opening 68.

A guide hole H is formed on the second extended portion 66b at a position where the lower spring SP2 does not interfere with a pair of opposing pairs of guide holes H, The guide bar G is inserted and fixed on the opposed faces of the pair of opposed second extensions 66b.

Therefore, when it is necessary to adjust the distance between the power transmission lines 1, the pushing knob 64 is pushed.

Then, the fitting hole 62 moves toward the inner diameter center of the upper rod 21a, and the upper spring SP1 and the lower spring SP2 are compressed at this time.

At the same time, the latching opening (68) enters into the height adjusting hole (56).

Therefore, the position of the lower rod (21b), that is, the height of the lower rod (21b) can be adjusted because the lower rod (21b) hung on the hooking hole (68)

Thus, when the pushing knob 64 is released after the height is adjusted, the elastic returning force of the upper spring SP1 and the lower spring SP2 causes the fitting hole 62 and the hooking hole 68 to return to their original positions The upper rod 21a and the lower rod 21b are inserted into the height adjusting holes 56 of the upper rod 21a and the lower rod 21b, respectively.

This makes it possible to install a more smooth and easy spacer.

The installation process of the space of the transmission line 1 having such a structure will be described as follows.

First, the clamping unit 30 and the impact absorbing unit 20 are fastened to the main body 10 according to the number of transmission lines 1 to be joined on the ground.

If the number of transmission lines 1 is three, three of the six bosses 11 provided on the main body 10 are selected to have equal intervals and the impact absorbing unit 20 is fastened to each boss 11.

The rod 21 is inserted into the sliding hole 12 from the upper portion of the boss 11 and the spring 26 is positioned so as to surround the outer circumferential surface of the rod 21 extending below the boss 11. [

Thereafter, when the lower end of the rod 21 is coupled through the engaging member 25, the spring 26 comes into contact with the lower surface of the boss 11 and the other side comes into contact with the engaging member 25, The elastic force is exerted at the time of ascending and descending.

When the shock-absorbing unit 20 is completed, the clamping unit 30 is engaged with the upper portion of the rod 21 installed.

When the installation of the clamping unit 30 is completed, the worker moves up to a position adjacent to the transmission line 1 to join the clamping unit 30 to the transmission line 1, thereby completing the installation of the spacer 100 of the transmission line.

10: Main body 20: Shock absorption unit
30: Clamping unit

Claims (1)

In the spacer for maintaining the spacing of the transmission line 1,
A body 10 including a boss 11 having a hexagonal shape and a hollow formed therein and having sliding holes 12 extending radially from the center; A rod 21 which is coupled to the boss 11 so as to be pulled in and pulled out along the sliding hole 12 and a rod 21 which is screwed to the end of the rod 21 and has a larger diameter than the sliding hole 12 And a spring 26 which surrounds the outer circumferential surface of the rod 21 and has one side abutting against the lower end of the boss 11 and the other abutting against the upper end of the engaging member 25, A shock absorber unit (20) comprising; And a clamping unit 30 coupled to an upper end of the rod 21. The clamping unit 30 is formed to be able to support the transmission line 1 for a predetermined length and protrudes outward on one side, A lower member 35 having a plurality of first engaging portions 36 formed with an engaging hole 37 penetrating the upper and lower surfaces of the lower member 35 and a lower member 35 hinged to one side of the lower member 35 in a rotatable manner, And an upper member (31) having a second engaging portion (32) formed with a locking protrusion so as to be detachably coupled to the engaging hole (37) of the first engaging portion (36) Two guide grooves 13 extending downward along the longitudinal direction of the boss 11 from the upper end are provided on the inner surface of the boss 11 so as to guide the lifting direction of the boss 11, 21 are formed with guide projections 23 which move along the guide grooves 13, The clamping unit 30 includes an air passage hole 39 for communicating the inside and the outside with the upper member 31 and the lower member 35 so as to prevent moisture from being caught on the outer circumferential surface of the transmission line 1 to be coupled, And a groove (40) for providing a movement path through which the air introduced from the outside along the inner peripheral surface of the member (31) and the lower member (35) can move; The rod 21 further includes a length adjusting means 50. In order to install the length adjusting means 50, the rod 21 is formed in a hollow cylindrical shape, A pair of operating holes 52 are formed in a part of the length of the upper rod 21a so as to be diametrically opposed to each other and a lower portion of the lower portion of the operating rod 52 A plurality of height adjusting holes 56 are formed through the height adjusting portion 54 at regular intervals in the longitudinal direction, The upper rod 21a has a stepped portion to be fitted to the height adjusting portion 54. When the upper rod 21a is fitted into the height adjusting portion 54 which is the lower end of the upper rod 21a, 21b are provided with a plurality of holes corresponding to the height adjusting holes 56, And a height adjusting member 60 is fitted to the height adjusting hole 56 of the upper rod 21a and the height adjusting member 60 is fixed to the upper end of the upper rod 21a, And the upper end of the fitting hole 62 is partially exposed to the outside through the operating hole 52 and the upper spring SP1 is fitted to the opposite end thereof And upper and lower ends orthogonal to the upper and lower ends are hooked to the inside of the operating hole 52 to stop the fitting opening 62 from escaping to the outside, And a pushing knob (64) is screwed to the distal end surface of the fitting member (62), and the fitting member 62 is formed with a first extended portion 66a extending obliquely toward the center of the inner diameter of the upper rod 21a, A second extending portion 66b extending in the vertical direction is formed at the lower end of the first extending portion 66a and a second extending portion 66b is formed at the lower end of the second extending portion 66b in a direction opposite to the first extending portion 66a And a third extension 66c extending obliquely to the second extension 66c is formed at the end of the third extension 66c and a hook 68 extending parallel to the insertion hole 62 is formed at the end of the third extension 66c, A lower spring SP2 is engaged and fixed between the second extended portions 66b for activating an operating source of the lower spring SP2 and the second spring SP2, A guide hole H is formed on the extended portion 66b such that a pair of opposing pairs of the guide holes G are displaced from each other and a guide bar G is inserted into the guide hole H, Is fixed on the opposite surface of the second extended portion (66b) of the second transmission portion (66b).

Images