TWI636205B - Structures of outer chain link and link plate - Google Patents

Abstract

The invention relates to a chain structure, which is provided with a chain body, and the two ends of the chain body are respectively provided with a joint portion, and the two joint portions are respectively provided with a shaft hole penetrating therethrough. A lower waist portion is disposed between the two joint portions, and the two side edges of the waist portion are respectively provided with a first chamfer. The waist portion is further provided with a groove, and the maximum width dimension of the groove relative to the vertical direction between the two joint portions is 20% to 60% of the minimum width dimension of the waist in the same direction. Further, the present invention relates to an outer link, which is formed by pivoting a first outer link and a second outer link which are identical to the structure of the link body. By means of the bicycle shifting, when the sprocket of the toothed disc is engaged or disengaged from the chain, no obstacle or noise is generated, and the shifting can be smoothly performed.

Description

Outer link and chain structure

The present invention relates to a chain structure and an outer chain link which can be smoothly operated without causing obstruction when the chain is shifted.

Generally, the shifting mechanism of a bicycle usually shifts the chain between the large gear and the pinion by a derailleur. However, no matter whether the chain is to be detached or jammed between the large and small gears, it will cause the chain outside the chain and the gears of the large and small gears to be hindered, so as to affect the smooth operation during shifting.

Therefore, there is a patent entitled "Bicycle Chain" No. 201538870 published by the Republic of China on October 16, 104, which discloses an outer link plate member that can be used for a bicycle chain. The outer link plate member has an inner surface that is constructed to face the outer pair of outer link plates in the assembled state, and an outer surface opposite the inner surface. The outer link plate member has an outer periphery and first and second end portions respectively including first and second openings, and the first and second openings each have respective mutually parallel central axes. The intermediate portion is configured to interconnect the first end portion with the second end portion. The intermediate portion has an axially concave portion formed along the outer periphery on the outer surface, the intermediate portion having a pair of intermediate edges formed along the outer periphery, and the axially concave portion is formed in the pair of intermediate edges At least one of the at least one of the pair of intermediate edges includes a chamfered portion that connects the outer surface of the outer link plate member.

The patent is only provided with a chamfered portion on the outer periphery of the second outer link plate member, so that the chain can be smoothly inserted into the large and small gears during shifting, but the structure is smooth for the operation of the shifting. There are still deficiencies that cannot achieve the best shifting effect.

Therefore, in view of the fact that the current chain has the above disadvantages in shifting. Therefore, the present invention provides a chain structure, which is provided with a chain body, and the two ends of the chain body are respectively provided with a pair of joint portions, and the two joint portions are respectively provided with a shaft hole penetrating through, and the two joints are respectively combined. Between the portions, a waist portion is provided, and the two sides of the waist portion are respectively provided with a first chamfer, and the waist portion is provided with a groove, and the groove is perpendicular to the two joint portions. The maximum width dimension of the direction is 20% to 60% of the minimum width dimension of the waist in the same direction.

A second chamfer is respectively disposed around the circumference of the two joint portions.

The two second chamfers are respectively disposed at half of the circumference of the two joint portions.

The two second chamfers are symmetrical with respect to each of the two halves of the circumference of the two joints.

The invention may also be an outer link, which is formed by pivoting a first outer link piece and a second outer link piece, and the two ends of the first outer link piece are respectively provided with a first one of the opposite ends. The first joint portion is respectively provided with one of the first shaft holes, and the first joint portion is provided with a first waist portion which is depressed, and the two sides of the first waist portion. a first chamfer is respectively disposed, and a first groove is disposed on the first waist portion, and a maximum width dimension of the first groove relative to a vertical direction between the two first joint portions is in the same direction The first waist has a minimum width dimension of 20% to 60%. The two ends of the second outer link are respectively provided with a second connecting portion, and the two second connecting portions are respectively provided with a second shaft hole, and the second connecting portion is disposed between the two ends. a second waist portion having a lower depression, wherein the second side of the second waist portion is respectively provided with a second chamfer, and the second waist portion is provided with a second groove, the second groove is opposite to the second The maximum width dimension in the vertical direction between the two second joint portions is 20% to 60% of the minimum width dimension of the second waist portion in the same direction. The pivoting direction of the first outer chain piece and the second outer chain piece is the first chamfer of the first outer chain piece, and the first part of the second outer chain piece The two chamfers are all mounted toward the outer side of the outer link, and the outer direction of the outer link refers to the right direction when the bicycle is advanced.

The circumferences of the two first joint portions are respectively provided with a third chamfer, and the circumferences of the two second joint portions are respectively respectively provided with a fourth chamfer, and the two third chamfers are respectively placed in a wrong manner. Each of the two first and second chamfers is symmetrical with respect to each of the two second joint portions.

The invention may also be an outer link, which is formed by pivoting a first outer link piece and a second outer link piece, and the two ends of the first outer link piece are respectively provided with a first one of the opposite ends. The first joint portion is respectively provided with one of the first shaft holes, and the first joint portion is provided with a first waist portion which is depressed, and the two sides of the first waist portion. a first chamfer is respectively disposed, and a first groove is disposed on the first waist portion, and a maximum width dimension of the first groove relative to a vertical direction between the two first joint portions is in the same direction The first waist has a minimum width dimension of 20% to 60%. The two ends of the second outer link are respectively provided with a second connecting portion, and the two second connecting portions are respectively provided with a second shaft hole, and the second connecting portion is disposed between the two ends. a second waist portion having a lower depression, wherein the second side of the second waist portion is respectively provided with a second chamfer, and the second waist portion is provided with a second groove, the second groove is opposite to the second The maximum width dimension in the vertical direction between the two second joint portions is 20% to 60% of the minimum width dimension of the second waist portion in the same direction. The pivoting 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 side of one of the outer link pieces, and The second chamfer of the second outer link is mounted toward an inner side of the outer link, and the outer direction of the outer link refers to a right direction when the bicycle is advanced. The inner direction of the outer link refers to the left direction when the bicycle is advanced.

The circumferences of the two first joint portions are respectively provided with a third chamfer, and the circumferences of the two second joint portions are respectively respectively provided with a fourth chamfer, and the two third chamfers are respectively placed in a wrong manner. Each of the two first and second chamfers is symmetrical with respect to each of the two second joint portions.

The invention may also be an outer link, which is formed by pivoting a first outer link piece and a second outer link piece, and the two ends of the first outer link piece are respectively provided with a first one of the opposite ends. The first joint portion is respectively provided with one of the first shaft holes, and the first joint portion is provided with a first waist portion which is depressed, and the two sides of the first waist portion. a first chamfer is respectively disposed, and a first groove is disposed on the first waist portion, and a maximum width dimension of the first groove relative to a vertical direction between the two first joint portions is in the same direction The first waist has a minimum width dimension of 20% to 60%. The two ends of the second outer link are respectively provided with a second connecting portion, and the two second connecting portions are respectively provided with a second shaft hole, and the second connecting portion is disposed between the two ends. a second waist portion having a lower depression, wherein the second side of the second waist portion is respectively provided with a second chamfer, and the second waist portion is provided with a second groove, the second groove is opposite to the second The maximum width dimension in the vertical direction between the two second joint portions is 20% to 60% of the minimum width dimension of the second waist portion in the same direction. Having at least a complex array outer link, any single array of the outer link of the outer link and the second outer link of the outer link, and the outer chain of any even array The pivotal joining direction of the first outer chain piece and the second outer chain piece is opposite.

The circumferences of the two first joint portions are respectively provided with a third chamfer, and the circumferences of the two second joint portions are respectively respectively provided with a fourth chamfer, and the two third chamfers are respectively placed in a wrong manner. Each of the two first and second chamfers is symmetrical with respect to each of the two second joint portions.

According to the above technical features, the following advantages are obtained:

1. By the guiding action of the first chamfering and the second chamfering of the chain body, the chain can be prevented from being disturbed or noiseed when shifting, and the shifting can be smoothly performed.

2. The outer chain piece has a depressed waist portion and a groove, so that the introduction pitch between the two outer outer chain pieces can be made wider, and when shifting, the sprocket can be more quickly engaged.

3. The first outer chain piece and the second outer chain piece of the outer chain link can be installed in different pivoting joint directions, so that the chain does not hinder or emit noise when shifting in any direction, and can be quickly Complete the shift.

(1) ‧‧‧Legoscope body

(11) ‧ ‧ joints

(12)‧‧‧Axis hole

(13) ‧‧‧ Waist

(14)‧‧‧First chamfer

(15)‧‧‧Second chamfer

(16) ‧‧‧ Groove

(1A)‧‧‧First outer link

(11A) ‧ ‧ First Joint Department

(12A)‧‧‧First shaft hole

(13A) ‧‧‧First waist

(14A)‧‧‧First chamfer

(15A)‧‧‧ Third chamfer

(16A)‧‧‧First groove

(1B)‧‧‧Second outer chain

(11B) ‧ ‧ second joint

(12B)‧‧‧Second shaft hole

(13B)‧‧‧Second waist

(14B) ‧‧‧second chamfer

(15B)‧‧‧ Fourth chamfer

(16B)‧‧‧second groove

(2A)‧‧‧Internal links

(3A)‧‧‧Chain

(C) ‧ ‧ sprocket

(D) ‧‧‧ minimum width dimension of the waist

(d) ‧‧‧ maximum width dimension of the groove

(E)‧‧‧Introduction spacing

(F) ‧‧‧The direction of bicycle advancement

(F1)‧‧‧Outside direction

(F2)‧‧‧Inside direction

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

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

[Third image] is a perspective view of the first outer chain piece and the second outer chain piece according to 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 cross-sectional view taken along the line V-V of the fourth drawing of the present invention.

[Sixth] is a schematic view showing the first outer link piece and the second outer link piece of the second embodiment of the present invention being mounted toward the outer side of the outer link.

[Seventh] is a schematic view showing the first outer link piece facing the outer side of the outer link and the second outer link facing the inner side of the outer link according to the second embodiment of the present invention.

[Eighth image] is a schematic view showing the first outer chain piece and the second outer chain piece of the outer chain link of any one of the single array and the even array in the second embodiment of the present invention.

Referring to the first embodiment and the second figure, the first embodiment of the present invention is a chain structure, and is provided with a chain body (1), and the two ends of the chain body (1) are respectively provided with opposite sides. A joint portion (11) of a circular arc shape is provided with a shaft hole (12) penetrating therethrough, and a waist portion (13) is formed between the two joint portions (11). The second side of the waist (13) is respectively provided with a first chamfer (14), and the peripheral ring of the two joints (11) is provided with a second chamfer (15), the second chamfer (15) The collar is disposed at one half of the circumference of the joint portion (11), and the two second chamfers (15) are symmetrical with respect to each half of the circumference of the joint portion (11). The second chamfer (15) may also be completely looped around the periphery of the joint portion (11), or The second chamfer (15) is not disposed at the periphery of the joint portion (11), and all of the embodiments of the present invention may include an embodiment. Further, the waist portion (13) is provided with a groove (16), and the maximum width dimension (d) of the groove (16) with respect to the vertical direction between the two joint portions (11) is the same direction of the waist portion. (13) 20% to 60% of the minimum width dimension (D).

Referring 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, the two ends of the first outer chain piece (1A) are respectively provided with a first joint portion (11A) opposite to the circular arc shape, and the first joint portion (11A) is provided with a first shaft hole penetrating therethrough. (12A), another first waist portion (13A) is provided between the two first joint portions (11A). The first side of the first waist portion (13A) is respectively provided with a first chamfer (14A), and the peripheral ring of the two first joint portions (11A) is provided with a third chamfer (15A), the third The chamfer (15A) ring is disposed at one half of the circumference of the first joint portion (11A), and the two third chamfers (15A) are symmetrical with respect to the circumference of the two first joint portions (11A). Each half. The third chamfer (15A) may also be completely looped around the circumference of the first joint portion (11A), or the third chamfer (15A) may not be disposed at the periphery of the first joint portion (11A). , all of which may include implementations of the invention. Further, a first groove (16A) is disposed on the first waist portion (13A), and a maximum width dimension (d) of the first groove (16A) relative to a vertical direction between the two first joint portions (11A) It is 20%~60% of the minimum width dimension (D) of the first waist (13A) in the same direction.

As shown in the third and fourth figures, the two ends of the second outer chain piece (1B) are respectively provided with a second joint portion (11B) opposite to the circular arc shape, and the second joint portion (11B) A second shaft hole (12B) is formed through the second shaft hole (12B), and a second waist portion (13B) is disposed between the two second joint portions (11B). Further, a second chamfer (14B) is disposed on each of the two sides of the second waist portion (13B), and a fourth chamfer (15B) is disposed on the peripheral loop of the second second joint portion (11B). The chamfer (15B) is disposed at a half of the circumference of the second joint portion (11B), and the two fourth chamfers (15B) are symmetrical with respect to the circumference of the second joint portion (11B). Each half. The fourth chamfer (15B) may also be completely looped around the circumference of the second joint portion (11B), or the fourth chamfer (15B) may not be disposed at the periphery of the second joint portion (11B). , all of which can be packaged by the present invention Contains the form of implementation. Further, a second groove (16B) is disposed on the second waist portion (13B), and a maximum width dimension (d) of the second groove (16B) relative to a vertical direction between the two second joint portions (11B) It is 20%~60% of the minimum width dimension (D) of the second waist portion (13B) in the same direction.

As shown in the fourth and fifth figures, the outer link is further coupled with the inner link of the two inner links (2A), and the outer link is respectively connected by a chain shaft (3A). The inner links are pivotally coupled, and can be assembled into a chain for meshing transmission and shifting with the sprocket of the plurality of sprocket wheels of a bicycle rear wheel, and the diameters of the spurs are arranged in an order of magnitude. The gradual increase in the outer direction (high speed) toward the inner direction (low speed). In the second embodiment of the present invention, the direction of the outer link is based on the direction in which the bicycle is advanced (F), and the direction of the right side of the bicycle traveling direction (F) is the outer side of the outer link (F1). ), and the direction of the left side of the riding direction (F) of the bicycle is the inner direction of the outer link (F2). The pivoting direction of the first outer chain piece (1A) and the second outer chain piece (1B) of each outer link of the chain is the first outer chain piece (1A) A chamfer (14A) and the second chamfer (14B) of the second outer link (1B) are both mounted toward the outer link direction (F1).

As shown in the third and sixth figures, when the chain starts to shift from the outer link direction (F1) toward the inner direction (F2) (shift from high speed to low speed), the chain of the chain When the tooth (C) is engaged between the first outer chain piece (1A) and the second outer chain piece (1B) of the chain, the element (C) is first inclined to abut the first In the first groove (16A) of the outer chain piece (1A), the element (C) is brought closer to the first outer chain piece (1A) to facilitate its movement for shifting. Then the sprocket (C) first contacts the first chamfer (14A) of the first outer slab (1A), and the first chamfer (14A) smoothly snaps into the first outer The chain piece (1A) and the second outer chain piece (1B) can be quickly shifted without causing obstruction or noise.

As shown in the third and sixth figures, when the gear shift is required again, the chain gear (C) is between the first outer chain piece (1A) and the second outer chain piece (1B) which are separated from the chain. The sprocket (C) will contact the second chamfer (14B) of the second outer gusset (1B), and the second chamfer (14B) smoothly detaches from the first Between the outer link piece (1A) and the second outer link piece (1B), without hindering or making noise, it can be quickly completed from the outer direction (F1) of the outer link to the inner direction (F2). Variable speed (shift from high speed to low speed). Moreover, due to the continuous rotation of the chain, the sprocket (C) is engaged between the first outer chain piece (1A) and the second outer chain piece (1B) which are engaged or disengaged from the chain. And contacting the third chamfer (15A) or the fourth chamfer (15B), which can also be guided by the third chamfer (15A) or the fourth chamfer (15B). The sprocket (C) does not cause obstruction or noise, but can smoothly complete the shift.

As shown in the third and sixth figures, the second outer link piece (1B) of the second outer link piece (1B) is simultaneously depressed with the second waist portion (13B) and the second groove (13B) 16B), and may have a larger lead-in spacing (E) between the other first outer chain piece (1A), so that the gear element (C) can be quickly guided into the first when shifting. Between the outer chain piece (1A) and the second outer chain piece (1B), and the second waist portion (13B) of the second outer chain piece (1B) and the first outer chain piece (1A) Within the space.

As shown in the seventh embodiment, the second embodiment of the present invention can also convert the first outer link piece (1A) and the second outer link piece (1B) into a pivotal 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 mounted toward the outer side (F1) of the outer link. The second chamfer (14B) of the second outer link piece (1B) is mounted toward the inner side (F2) of the outer link.

As shown in the third and seventh figures, when the chain starts to shift from the outer side (F1) to the inner side (F2) (the high speed shift is the low speed), the chain of the chain When the tooth (C) is engaged between the first outer chain piece (1A) and the second outer chain piece (1B) of the chain, the element (C) is first inclined to abut the first In the first groove (16A) of the outer chain piece (1A), the element (C) is brought closer to the first outer chain piece (1A) to facilitate its movement for shifting. Then the sprocket (C) first contacts the first chamfer (14A) of the first outer slab (1A), and the first chamfer (14A) smoothly snaps into the first outer Between the chain piece (1A) and the second outer chain piece (1B), no shifting or noise is generated, and the shifting can be completed quickly.

As shown in the third and seventh figures, when the chain is shifted from the inner side direction (F2) of the outer link to the outer direction (F1) (shifting from the low speed to the high speed), the chainring When the sprocket (C) is engaged between the second outer chain piece (1B) of the chain and the first outer chain piece (1A), the sprocket (C) is first tilted against the first The second groove (16B) of the two outer chain pieces (1B) brings the element (C) closer to the second outer chain piece (1B) to facilitate its movement for shifting. Then the sprocket (C) first contacts the second chamfer (14B) of the second outer slab (1B), and smoothly fits the second outer chamfer (14B) along the second chamfer (14B). The chain piece (1B) is interposed between the first outer chain piece (1A). Therefore, the chain is shifted from the outer side (F1) to the inner side (F2) (shift from the high speed to the low speed) or from the inner side (F2) to the outer side (F1) (by the low speed) The shifting speed is a high-speed gear), which does not cause obstruction or noise, and can quickly complete the shifting.

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 one of the outer links of the chain is adjacent to the other adjacent one. The pivotal joint direction of the first outer link piece (1A) and the second outer link piece (1B) of the outer link portion is opposite. That is, the first chamfer (14A) of the first outer link (1A) of the outer link of the single array on the chain and the second chamfer (14B) of the second outer link (1B) Both are mounted toward the outer side of the outer link (F1). And 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 Installed toward the inside direction (F2) of the outer link. Therefore, the chain is shifted from the outer side (F1) to the inner side (F2) (shift from the high speed to the low speed) or from the inner side (F2) to the outer side (F1) (by the low speed) The shifting speed is a high-speed gear), which does not cause obstruction or noise, and can quickly complete the shifting.

However, the above description is only two of the embodiments of the present invention, and the scope of the patent application and the scope of the description of the present invention are not limited thereto. It is still within the scope of the protection covered by the scope of the invention.

Claims (4)

A chain structure is provided with a chain body, and two ends of the chain body are respectively provided with a pair of joint portions, and the two joint portions are respectively provided with a through hole and a joint between the two joint portions. a waist portion having a depression, a side edge of each of the waist portions is respectively provided with a first chamfer, and a groove is disposed at the waist portion, and a maximum width of the groove relative to a vertical direction between the two joint portions The size is 20%~60% of the minimum width dimension of the waist in the same direction, the circumference of the two joints is respectively provided with a second chamfer, and the two second chamfers are respectively symmetrical. Each half of the circumference of the two joints. An outer link is formed by pivoting a first outer link and a second outer link, and the two ends of the first outer link are respectively provided with a first joint, The first joint portion is respectively provided with a first shaft hole, and the first joint portion is provided with a first waist portion which is depressed, and the first side of the first waist portion is respectively provided with a first shaft portion. a chamfer, and a first groove is disposed on the first waist portion, and a maximum width dimension of the first groove relative to a vertical direction between the two first joint portions is the first direction in the same direction 20%~60% of the minimum width dimension of the waist; the two ends of the second outer chain piece are respectively provided with one of the second joint portions, and the two second joint portions are respectively provided with one of the second shaft holes. Further, a second lower waist portion is disposed between the two second joint portions, and a second chamfer is disposed on each of the two sides of the second waist portion, and a second concave portion is disposed on the second waist portion. a groove, a maximum width dimension of the second groove relative to a vertical direction between the two second joint portions, wherein the second waist portion is the same direction 20%~60% of the small width dimension, a circumference of the second joint portion is respectively provided with a third chamfer, and a circumference of the second joint portion is respectively provided with a fourth chamfer, the second The three chamfers are respectively erroneously disposed at each half of the circumference of the two first joint portions, and the two fourth chamfers are erroneously placed at half of the circumference of the two second joint portions; The pivoting direction of the first outer chain piece and the second outer chain piece is to form the first chamfer, the third chamfer, and the second outer chain of the first outer chain piece The second chamfer and the fourth chamfer of the sheet are toward Attached to the outer link in an outer direction, the outer direction of the outer link refers to the right direction when the bicycle is advanced. An outer link is formed by pivoting a first outer link and a second outer link, and the two ends of the first outer link are respectively provided with a first joint, The first joint portion is respectively provided with a first shaft hole, and the first joint portion is provided with a first waist portion which is depressed, and the first side of the first waist portion is respectively provided with a first shaft portion. a chamfer, and a first groove is disposed on the first waist portion, and a maximum width dimension of the first groove relative to a vertical direction between the two first joint portions is the first direction in the same direction 20%~60% of the minimum width dimension of the waist; the two ends of the second outer chain piece are respectively provided with one of the second joint portions, and the two second joint portions are respectively provided with one of the second shaft holes. Further, a second lower waist portion is disposed between the two second joint portions, and a second chamfer is disposed on each of the two sides of the second waist portion, and a second concave portion is disposed on the second waist portion. a groove, a maximum width dimension of the second groove relative to a vertical direction between the two second joint portions, wherein the second waist portion is the same direction 20%~60% of the small width dimension, a circumference of the second joint portion is respectively provided with a third chamfer, and a circumference of the second joint portion is respectively provided with a fourth chamfer, the second The three chamfers are respectively erroneously disposed at each half of the circumference of the two first joint portions, and the two fourth chamfers are erroneously placed at half of the circumference of the two second joint portions; The pivoting direction of the first outer chain piece and the second outer chain piece is to direct the first chamfer and the third chamfer of the first outer chain piece toward the outer link Installed in an outer direction, and the second chamfer and the fourth chamfer of the second outer link are mounted toward an inner side of the outer link, and the outer direction of the outer link refers to riding In the right direction when the bicycle is advanced, the inner direction of the outer link refers to the left direction when the bicycle is advanced. An outer link is formed by pivoting a first outer link and a second outer link, and the two ends of the first outer link are respectively provided with a first joint, The first joint portion is respectively provided with one of the first shaft holes, and the first joint portion is provided with a first waist portion which is depressed, and the The first side of the first waist portion is respectively provided with a first chamfer, and the first waist portion is provided with a first groove, and the first groove is opposite to the vertical direction between the two first joint portions. The width dimension is 20%~60% of the minimum width dimension of the first waist portion in the same direction; the two ends of the second outer chain piece are respectively provided with one of the second joint portions, and the second second combination a second shaft hole is disposed through the second shaft hole, and a second waist portion is disposed between the two second joint portions, and the second side of the second waist portion is respectively provided with a second chamfer. The second waist portion is further provided with a second groove, and the maximum width dimension of the second groove relative to the vertical direction between the two second joint portions is the minimum width of the second waist portion in the same direction. 20%~60% of the size, the circumference of the two first joints is respectively provided with a third chamfer, and the circumference of the two second joints is respectively provided with a fourth chamfer, and the second and third The symmetry of the horns is respectively placed at each half of the circumference of the two first joints, and the two fourth chamfers are opposite Each of the two outer joints is disposed at least one half of the circumference of the second joint portion; at least one outer array of outer links, any single array of the first outer link and the second outer chain of the outer link The pivotal joint direction of the sheet is opposite to the pivotal joint direction of the first outer link and the second outer link of the outer link of any even array.