TW201800684A - Structures of outer chain link and link plate - Google Patents

Abstract

A structure of a link plate includes a plate body having two connection portions disposed respectively at two ends thereof and a concave midsection extending between the two connection portions. Each connection portion has a penetrated pinhole. At the outer edge of the concave midsection a first chamfer is located. A groove is disposed at the midsection and a widest cross-sectional width of the groove along the extension is equal to or less than 20% to 60% of the smallest cross-sectional width of the midsection. The present invention also provides an outer chain link including a first outer link plate identical to the aforementioned link plate and a second outer link plate pivotally connected to the first outer link plate. During the shifting operation, the chain tooth of the chain wheel, without obstruction, may effectively engage or disengage the chain, while the shifting operation is executed smoothly and quietly.

Description

Outer link and link structure

The invention relates to a chain piece structure and outer links that can cause smooth operation when the chain is shifted.

Generally, the speed change mechanism of a bicycle is usually converted between a large gear and a small gear by a derailleur. However, when the chain is to be detached from or locked in between the large and small gears, it will cause obstacles outside the chain and the teeth of the large and small gears, which will affect the smooth operation during shifting.

Therefore, there is the Patent No. 201538870 "Bicycle Chain" patent published on October 16, 104, Republic of China, which discloses: an outer link plate that can be used for bicycle chains. The outer link plate has an inner surface that is constructed to face another mating outer link plate in an assembled state, and an outer surface opposite to the inner surface. The outer link plate has an outer periphery and first and second end portions respectively including first and second openings, and each of the first and second openings has a corresponding parallel central axis. The middle portion is arranged to interconnect the first end portion and the second end portion. The middle portion has an axial concave portion formed along the outer periphery on the outer surface, the middle portion has a pair of intermediate edges formed along the outer periphery, and the axial concave portion is formed in the pair of intermediate edges. And at least one of the chamfered portions includes a chamfered portion connecting the at least one of the pair of intermediate edges to an outer surface of the outer link plate.

The pre-patent case is only provided with a chamfered portion on the outer periphery of the second outer link plate, so that the chain can be smoothly locked into the large and small gears when changing speeds. However, these structures provide smooth operation for changing speeds. There are still shortcomings to achieve the best shifting effect.

Therefore, it is considered that the current chain has the above-mentioned disadvantages when shifting speed. Therefore, the present invention provides a chain link structure, which is provided with a chain link body. Two opposite ends of the chain link body are respectively provided with an opposite one joint portion, the two joint portions are respectively provided with a through shaft hole, and the two joints are A waist portion is provided between the lower portions, a first chamfer is provided on each side of the waist portion, and a groove is provided on the waist portion, and the groove is perpendicular to the two joint portions. The maximum width dimension in the direction is 20% to 60% of the minimum width dimension of the waist in the same direction.

A second chamfer is respectively provided on the periphery of the two joints.

The two second and second chamfers are respectively arranged on a half of a peripheral edge of the two joints.

The two second and second chamfers are symmetrically disposed on each half of the periphery of the two joints.

The present invention may also be an outer link, which is formed by relatively pivoting a first outer link and a second outer link, and two opposite ends of the first outer link are respectively provided with a first combination. Part, the two first joint parts are respectively provided with a first shaft hole penetrating therebetween, and the two first joint parts are provided with a low waisted first waist part, and two sides of the first waist part A first chamfer is respectively provided, and a first groove is provided at the first waist, and the maximum width dimension of the first groove with respect to the vertical direction between the two first joints is the same direction. 20% to 60% of the minimum width of the first waist. Two opposite ends of the second outer link are respectively provided with a second joint portion, the two second joint portions are respectively provided with a second shaft hole penetrating therebetween, and the two second joint portions are provided between the two second joint portions. There is a second waist with a low depression, and a second chamfer is respectively provided on two sides of the second waist, and a second groove is provided on the second waist, and the second groove is opposite to the second groove. The maximum width dimension in the vertical direction between the two second joints is 20% to 60% of the minimum width dimension of the second waist in the same direction. The pivotal joint direction of the first outer link piece and the second outer link piece is the first chamfer of the first outer link piece and the first chamfer of the second outer link piece. Both chamfers are installed in the outer direction of the outer link, and the outer direction of the outer link is the right direction when riding a bicycle forward.

A third chamfer is respectively provided around the periphery of the two first joints, a fourth chamfer is provided around the periphery of the second and second joints, and the second and third chamfers are symmetrically placed separately. Each half of the periphery of the two first joints, and the second and fourth chamfers are symmetrically placed on each half of the periphery of the second and second joints.

The present invention may also be an outer link, which is formed by relatively pivoting a first outer link and a second outer link, and two opposite ends of the first outer link are respectively provided with a first combination. Part, the two first joint parts are respectively provided with a first shaft hole penetrating therebetween, and the two first joint parts are provided with a low waisted first waist part, and two sides of the first waist part A first chamfer is respectively provided, and a first groove is provided at the first waist, and the maximum width dimension of the first groove with respect to the vertical direction between the two first joints is the same direction. 20% to 60% of the minimum width of the first waist. Two opposite ends of the second outer link are respectively provided with a second joint portion, the two second joint portions are respectively provided with a second shaft hole penetrating therebetween, and the two second joint portions are provided between the two second joint portions. There is a second waist with a low depression, and a second chamfer is respectively provided on two sides of the second waist, and a second groove is provided on the second waist, and the second groove is opposite to the second groove. The maximum width dimension in the vertical direction between the two second joints is 20% to 60% of the minimum width dimension of the second waist in the same direction. The pivoting and combining direction of the first outer link piece and the second outer link piece is to install the first chamfer of the first outer link piece toward an outer direction of one of the outer links, and The second chamfer of the second outer link is installed toward an inner direction of one of the outer links, and the outer direction of the outer link is a right direction when riding a bicycle, and the The inside direction of the outer link refers to the left direction when riding a bicycle forward.

A third chamfer is respectively provided around the periphery of the two first joints, a fourth chamfer is provided around the periphery of the second and second joints, and the second and third chamfers are symmetrically placed separately. Each half of the periphery of the two first joints, and the second and fourth chamfers are symmetrically placed on each half of the periphery of the second and second joints.

The present invention may also be an outer link, which is formed by relatively pivoting a first outer link and a second outer link, and two opposite ends of the first outer link are respectively provided with a first combination. Part, the two first joint parts are respectively provided with a first shaft hole penetrating therebetween, and the two first joint parts are provided with a low waisted first waist part, and two sides of the first waist part A first chamfer is respectively provided, and a first groove is provided at the first waist, and the maximum width dimension of the first groove with respect to the vertical direction between the two first joints is the same direction. 20% to 60% of the minimum width of the first waist. Two opposite ends of the second outer link are respectively provided with a second joint portion, the two second joint portions are respectively provided with a second shaft hole penetrating therebetween, and the two second joint portions are provided between the two second joint portions. There is a second waist with a low depression, and a second chamfer is respectively provided on two sides of the second waist, and a second groove is provided on the second waist, and the second groove is opposite to the second groove. The maximum width dimension in the vertical direction between the two second joints is 20% to 60% of the minimum width dimension of the second waist in the same direction. It includes at least a complex array of external links. The pivotal combination direction of the first external link and the second external link of any single array of the external links is related to the external link of any even array. The joint direction of the first outer link and the second outer link is opposite.

A third chamfer is respectively provided around the periphery of the two first joints, a fourth chamfer is provided around the periphery of the second and second joints, and the second and third chamfers are symmetrically placed separately. Each half of the periphery of the two first joints, and the second and fourth chamfers are symmetrically placed on each half of the periphery of the second and second joints.

According to the above technical features, it has the following advantages:

1. Through the guiding effect of the first chamfer and the second chamfer of the chain body, the chain can be smoothly changed without causing obstacles or noise when shifting.

2. Utilizing the outer chain with a low waist and groove, the lead-in distance between the two outer chains can be made wider, and when the gear is shifted, the guide sprocket can be snapped in and engaged more quickly.

3. The first outer link and the second outer link of the outer link can be installed in different pivot joint directions, so when the chain is shifted from any direction, it will not cause obstruction or noise, and can quickly Complete the shift.

Please refer to the first and second figures. The first embodiment of the present invention is a chain structure, which is provided with a chain body (1), and two ends of the chain body (1) are respectively provided with opposite ends. A circular arc-shaped joint portion (11) is provided with a through-hole shaft hole (12), and a low-pitched waist portion (13) is provided between the two joint portions (11). A second chamfer (14) is provided on each of the two sides of the waist (13), and a second chamfer (15) and a second chamfer (15) are provided on the peripheral ring of the two joints (11). ) Ring is set on half of the peripheral edge of the joint (11), and the second and second chamfers (15) are symmetrically placed on each half of the periphery of the two joints (11). The second chamfer (15) can also be completely circled around the periphery of the joint (11), or the second chamfer (15) is not arranged at all around the periphery of the joint (11). Embodiments of the invention may include aspects of implementation. In addition, a groove (16) is provided on the waist (13), and the maximum width dimension (d) of the groove (16) with respect to the vertical direction between the two joints (11) is the waist in the same direction. (13) 20% to 60% of the minimum width dimension (D).

Please refer to the third and fourth figures. The second embodiment of the present invention is an outer link. The outer link is a first outer link (1A) and a second outer link (1B). Relatively pivoted. Wherein, two opposite ends of the first outer link piece (1A) are respectively provided with a first arc-shaped first joint portion (11A), and the first joint portion (11A) is provided with a first shaft hole penetrating therethrough. (12A), and a first waist portion (13A) with a low depression is provided between the two first joint portions (11A). A second chamfer (14A) is provided on two sides of the first waist (13A), and a third chamfer (15A) is provided on the peripheral ring of the two first joints (11A). The chamfer (15A) is located halfway around the peripheral edge of the first joint (11A), and the second and third chamfers (15A) are symmetrically placed at the periphery of the two first joints (11A). Each half. The third chamfer (15A) may also be completely circumscribed on the periphery of the first joint (11A), or the third chamfer (15A) may not be provided on the periphery of the first joint (11A). Are all aspects of the invention that may include implementation. In addition, a first groove (16A) is provided on the first waist portion (13A), and a maximum width dimension (d) of the first groove (16A) in a vertical direction with respect to the two first joint portions (11A) , Which is 20% to 60% of the minimum width dimension (D) of the first waist (13A) in the same direction.

As shown in the third and fourth figures, two ends of the second outer link piece (1B) are respectively provided with a second arc-shaped second joint portion (11B), and the second joint portion (11B) A second shaft hole (12B) is provided therethrough, and a low waisted second waist portion (13B) is provided between the two second joint portions (11B). A second chamfer (14B) is provided on each of the two sides of the second waist (13B), and a fourth chamfer (15B) is provided on the peripheral ring of the second second joint (11B). The chamfer (15B) is located halfway around the periphery of the second joint (11B), and the second and fourth chamfers (15B) are symmetrically placed at the periphery of the second and second joint (11B). Each half. Also, the fourth chamfer (15B) may be completely looped around the periphery of the second joint (11B), or the fourth chamfer (15B) may not be arranged at all around the periphery of the second joint (11B). Are all aspects of the invention that may include implementation. In addition, a second groove (16B) is provided on the second waist portion (13B), and a maximum width dimension (d) of the second groove (16B) in a vertical direction with respect to the two second joint portions (11B) , Which is 20% to 60% of the minimum width dimension (D) of the second waist (13B) in the same direction.

As shown in the fourth and fifth figures, if the outer link is matched with another inner link that is pivotally connected by two inner link pieces (2A), then the outer link and the The inner chain link is pivoted and combined, and can be assembled into a chain, which can be used for meshing transmission and gear shifting with the sprocket teeth of a plurality of gear wheels of a bicycle rear wheel, and the order of the diameter of the gear wheels , Gradually increases from the outer direction (high gear) toward the inner direction (low gear) of the outer link. In the second embodiment of the present invention, the direction of the outer link is based on the forward direction (F) of the riding bicycle, and the right direction of the forward direction (F) of the riding bicycle is the outer direction of the outer link (F1). ), And the left direction of the forward direction (F) of the bicycle is the inner direction (F2) of the outer link. The pivotal joint direction of the first outer link piece (1A) and the second outer link piece (1B) of each set of outer chain links on the chain is the first outer link piece (1A). A chamfer (14A) and the second chamfer (14B) of the second outer link (1B) are both installed toward the outer direction (F1) of the outer link.

As shown in the third and sixth figures, when the chain starts to shift from the outer direction (F1) to the inner direction (F2) of the outer link (shifting from high speed to low speed), the chain of the chainring When the tooth (C) is engaged between the first outer link piece (1A) and the second outer link piece (1B) of the chain, the sprocket (C) will first lean against the first Inside the first groove (16A) of the outer chain piece (1A), the sprocket (C) is closer to the first outer chain piece (1A) to facilitate its movement and speed change. Then, the sprocket (C) will first contact the first chamfer (14A) of the first outer link piece (1A), and smoothly click into the first outer chamfer along the first chamfer (14A). Between the chain piece (1A) and the second outer chain piece (1B), the speed change can be completed quickly without causing obstruction or noise.

As shown in the third and sixth figures, when the gear needs to be changed again, the chain tooth (C) is between the first outer link (1A) and the second outer link (1B) leaving the chain. At this time, the sprocket (C) will contact the second chamfer (14B) of the second outer chain piece (1B), and smoothly leave the first outer chain along the second chamfer (14B). Between the plate (1A) and the second outer link (1B) without causing obstruction or noise, and can quickly change the speed from the outer direction (F1) to the inner direction (F2) of the outer link ( (Shift from high gear to low gear). Because the chain continues to rotate at the same time as the speed is changed, whether the chain tooth (C) is engaged with or disengaged between the first outer link (1A) and the second outer link (1B) of the chain , Will also touch the third chamfer (15A) or the fourth chamfer (15B), can be guided by the third chamfer (15A) or the fourth chamfer (15B), can also make The sprocket (C) will not cause obstruction or make noise, but can smoothly shift speed.

As shown in the third and sixth figures, the second outer link (1B) and the second outer link (1B) having the second waist portion (13B) and the second recess ( 16B), it can have a larger lead-in distance (E) from the other first outer link (1A), so that the sprocket (C) can be quickly guided into the first when changing speed Between the outer link piece (1A) and the second outer link piece (1B), the second waist portion (13B) of the second outer link piece (1B) and the first outer link piece (1A) Within the space.

As shown in the seventh figure, in the second embodiment of the present invention, the first outer link piece (1A) and the second outer link piece (1B) can also be assembled to form a pivot joint direction of the outer link. That is, the first chamfer (14A) of the first outer link piece (1A) of each set of outer links on the chain is installed toward the outer direction (F1) of the outer link. The second chamfer (14B) of the second outer link (1B) is installed toward the inner direction (F2) of the outer link.

As shown in the third and seventh figures, when the chain starts to shift from the outer direction (F1) to the inner direction (F2) of the outer link (shifting from high speed to low speed), the chain of the chainring When the tooth (C) is engaged between the first outer link piece (1A) and the second outer link piece (1B) of the chain, the sprocket (C) will first lean against the first Inside the first groove (16A) of the outer chain piece (1A), the sprocket (C) is closer to the first outer chain piece (1A) to facilitate its movement and speed change. Then, the sprocket (C) will first contact the first chamfer (14A) of the first outer link piece (1A), and smoothly click into the first outer chamfer along the first chamfer (14A). Between the chain piece (1A) and the second outer chain piece (1B), no obstruction or noise is caused, and the speed change can be completed quickly.

As shown in the third and seventh figures, when the chain is shifted from the inner direction (F2) to the outer direction (F1) of the outer link (shifting from low gear to high gear), When the sprocket (C) engages and engages between the second outer link (1B) and the first outer link (1A), the sprocket (C) first leans against the first Inside the second groove (16B) of the two outer link pieces (1B), the sprocket (C) is closer to the second outer link piece (1B) to facilitate its movement and speed change. Then, the sprocket (C) will first contact the second chamfer (14B) of the second outer link (1B), and smoothly snap into the second outer along the second chamfer (14B). Between the link (1B) and the first outer link (1A). Therefore, whether the chain is shifted from the outer direction (F1) to the inner direction (F2) of the outer link (shift from high speed to low speed), or from the inner direction (F2) to outer direction (F1) (from low speed The gear shift is high-speed gear), which will not cause obstruction or make noise, and can complete the gear shift quickly.

As shown in the eighth figure, the pivotal joint direction of the first outer link piece (1A) and the second outer link piece (1B) of any set of outer links of the chain is another one that can be adjacent to it. The pivotal coupling direction of the first outer link piece (1A) and the second outer link piece (1B) of the outer link group of the group is opposite. That is, the first chamfer (14A) of the first outer link (1A) and the second chamfer (14B) of the second outer link (1B) of a single array of outer links on the chain All are mounted in the direction (F1) of the outer link. The first chamfer (14A) of the first outer link (1A) and the second chamfer (14B) of the second outer link (1B) of the outer link of the even array on the chain are both Install toward the inside (F2) of the outer link. Therefore, whether the chain is shifted from the outer direction (F1) to the inner direction (F2) of the outer link (shift from high speed to low speed), or from the inner direction (F2) to outer direction (F1) (from low speed The gear shift is high-speed gear), which will not cause obstruction or make noise, and can complete the gear shift quickly.

However, the above description is only two of the embodiments of the present invention. When the scope of patent protection of the present invention cannot be limited by this, for example, any simple equivalent changes and replacements made in accordance with the scope of patent application of the present invention and the contents of the description are It should still fall within the protection scope covered by the patent application scope of the present invention.

(1) ‧‧‧Chain body
(11) ‧‧‧Combination
(12) ‧‧‧Shaft hole
(13) ‧‧‧waist
(14) ‧‧‧The first chamfer
(15) ‧‧‧Second Chamfer
(16) ‧‧‧Groove
(1A) ‧‧‧First Outer Link
(11A) ‧‧‧First Joint
(12A) ‧‧‧First shaft hole
(13A) ‧‧‧First Waist
(14A) ‧‧‧The first chamfer
(15A) ‧‧‧ Third Chamfer
(16A) ‧‧‧First groove
(1B) ‧‧‧Second Outer Link
(11B) ‧‧‧Second Joint
(12B) ‧‧‧Second shaft hole
(13B) ‧‧‧Second Waist
(14B) ‧‧‧Second Chamfer
(15B) ‧‧‧Fourth chamfer
(16B) ‧‧‧Second groove
(2A) ‧‧‧Internal link
(3A) ‧‧‧Chain Shaft
(C) ‧‧‧Sprocket
(D) ‧‧‧Minimum width of waist
(d) ‧‧‧ the maximum width of the groove
(E) ‧‧‧ Leading distance
(F) ‧‧‧Bicycle's direction
(F1) ‧‧‧Outer direction
(F2) ‧‧‧ inside direction

[First image] This is a perspective external view of a chain body according to the first embodiment of the present invention.

[Second figure] is a plan view of the chain body according to the first embodiment of the present invention.

[Third figure] is a perspective external view of a first outer link and a second outer link of the second embodiment of the present invention.

[Fourth Figure] is a schematic view of a second embodiment of the present invention assembled into a chain.

[Fifth Figure] is a sectional view taken along the line V-V of the fourth figure of the present invention.

[Sixth Figure] is a schematic view showing that the first outer link piece and the second outer link piece are installed facing the outer direction of the outer link in the second embodiment of the present invention.

[Seventh Figure] It is a schematic diagram of the installation of the first outer link toward the outer side of the outer link and the second outer link toward the inner side of the outer link in the second embodiment of the present invention.

[Eighth Figure] It is a schematic diagram showing that the first outer link and the second outer link of the outer links of any single array and even array are respectively installed in opposite directions according to the second embodiment of the present invention.

(1) ‧‧‧Chain body

(11) ‧‧‧Combination

(12) ‧‧‧Shaft hole

(13) ‧‧‧waist

(14) ‧‧‧The first chamfer

(15) ‧‧‧Second Chamfer

(16) ‧‧‧Groove

Claims (10)

A chain link structure is provided with a chain link body. Two opposite ends of the chain link body are respectively provided with an opposite one joint portion, the two joint portions are respectively provided with a through shaft hole, and the two joint portions are provided between the two joint portions. There is a waist with a low depression. Two sides of the waist are respectively provided with a first chamfer, and a groove is provided at the waist. The maximum width of the groove with respect to the vertical direction between the two joints. The size is 20% to 60% of the minimum width of the waist in the same direction. According to the chain structure described in the first item of the patent application scope, a second chamfer is respectively provided on the peripheral edges of the two joint portions. According to the chain structure described in item 2 of the scope of the patent application, wherein the second and second chamfers are respectively disposed at half of a peripheral edge of the two joints. According to the chain structure described in item 2 of the scope of the patent application, wherein the second and second chamfers are symmetrically disposed on each half of the periphery of the two joints. An outer link is formed by relatively pivoting a first outer link and a second outer link. Two ends of the first outer link are respectively provided with a first first joint portion. The first joint portions are respectively provided with a first shaft hole penetrating, and between the two first joint portions are provided a low-profile first waist portion, and two sides of the first waist portion are respectively provided with a first Chamfering, and a first groove is provided at the first waist portion, and the maximum width dimension of the first groove with respect to the vertical direction between the two first joint portions is the first in the same direction The minimum width of the waist is 20% ~ 60%; the two ends of the second outer chain piece are respectively provided with a second second joint portion, and the second and second joint portions are respectively provided with a second shaft hole passing through, A second low waist is provided between the two second joints, and a second chamfer is provided on each of the two sides of the second waist, and a second concave is provided on the second waist. Slot, the maximum width dimension of the second groove with respect to the vertical direction between the two second joint portions is the second waist portion in the same direction 20% ~ 60% of the small width dimension; the pivotal joint direction of the first outer link piece and the second outer link piece is the first chamfer of the first outer link piece, and The second chamfers of the second outer link are all installed toward an outer direction of the outer link, and the outer direction of the outer link is a right direction when riding a bicycle forward. According to the outer chain link described in item 5 of the scope of the patent application, wherein the peripheral edges of the two first joints are respectively provided with a third chamfer, and the peripheral edges of the two second joints are provided with a fourth chamfer. The second and third chamfers are symmetrically placed on each half of the periphery of the second and first joints, and the second and fourth chamfers are symmetrically placed on each of the two second joints. Half of the perimeter. An outer link is formed by relatively pivoting a first outer link and a second outer link. Two ends of the first outer link are respectively provided with a first first joint portion. The first joint portions are respectively provided with a first shaft hole penetrating, and between the two first joint portions are provided a low-profile first waist portion, and two sides of the first waist portion are respectively provided with a first Chamfering, and a first groove is provided at the first waist portion, and the maximum width dimension of the first groove with respect to the vertical direction between the two first joint portions is the first in the same direction The minimum width of the waist is 20% ~ 60%; the two ends of the second outer chain piece are respectively provided with a second second joint portion, and the second and second joint portions are respectively provided with a second shaft hole passing through, A second low waist is provided between the two second joints, and a second chamfer is provided on each of the two sides of the second waist, and a second concave is provided on the second waist. Slot, the maximum width dimension of the second groove with respect to the vertical direction between the two second joint portions is the second waist portion in the same direction 20% ~ 60% of the small width dimension; the pivotal joint direction of the first outer link piece and the second outer link piece is such that the first chamfer of the first outer link piece faces the One of the outer links is installed in the outer direction, and the second chamfer of the second outer link is installed in the inner direction of one of the outer links, and the outer direction of the outer link refers to riding The right direction when traveling by bicycle, and the inner direction of the outer link means the left direction when traveling by bicycle. According to the outer chain link described in item 7 of the scope of the patent application, wherein the peripheral edges of the two first joints are respectively provided with a third chamfer, and the peripheral edges of the two second joints are respectively provided with a fourth chamfer. The second and third chamfers are symmetrically placed on each half of the periphery of the second and first joints, and the second and fourth chamfers are symmetrically placed on each of the two second joints. Half of the perimeter. An outer link is formed by relatively pivoting a first outer link and a second outer link. Two ends of the first outer link are respectively provided with a first first joint portion. The first joint portions are respectively provided with a first shaft hole penetrating, and between the two first joint portions are provided a low-profile first waist portion, and two sides of the first waist portion are respectively provided with a first Chamfering, and a first groove is provided at the first waist portion, and the maximum width dimension of the first groove with respect to the vertical direction between the two first joint portions is the first in the same direction The minimum width of the waist is 20% ~ 60%; the two ends of the second outer chain piece are respectively provided with a second second joint portion, and the second and second joint portions are respectively provided with a second shaft hole passing through, A second low waist is provided between the two second joints, and a second chamfer is provided on each of the two sides of the second waist, and a second concave is provided on the second waist. Slot, the maximum width dimension of the second groove with respect to the vertical direction between the two second joint portions is the second waist portion in the same direction 20% ~ 60% of the small width dimension; at least including a plurality of external links of the plurality of arrays, the pivotal joint direction of the first external link and the second external link of any single array of the external links, The direction of the pivotal connection between the first outer link piece and the second outer link piece of the outer link of any even array is opposite. According to the outer chain link described in item 9 of the scope of the patent application, wherein the peripheral edges of the two first joints are respectively provided with a third chamfer, and the peripheral edges of the two second joints are respectively provided with a fourth chamfer. The second and third chamfers are symmetrically placed on each half of the periphery of the second and first joints, and the second and fourth chamfers are symmetrically placed on each of the two second joints. Half of the perimeter.