TWI442121B - Plug connector and receptacle connector - Google Patents

Description

Plug connector and socket connector

The present invention relates to a connector, and more particularly to a plug connector and a socket connector that can transmit photoelectric signals.

The Universal Serial Bus (USB) interface is a standard input/output interface that has been widely used in the design of many electronic devices. In 1994, seven world-renowned computer and communication companies, including Intel, Compaq, Digital, IBM, Microsoft, NEC, and Northern Telecom, jointly established the USB Association (USB-IF) to initially establish a USB interface specification. So far, the USB Association has released versions 1.0, 1.1, 2.0 and 3.0, and the USB transfer rate has gradually improved. With the development of the electronics industry and the advancement of technology, people are still working hard to increase the transmission rate of USB.

The plug connector for transmitting optical signals in the prior art is used for abutment with a socket connector. The plug connector generally includes an insulative housing, a plurality of conductive terminals fixed on the insulative housing, and is mounted on the insulative housing for light. a fiber optic device for signal transmission, the optical fiber device comprising an embedded lens and an optical fiber optically coupled to the lens, wherein the optical fiber device of the plug connector can generate an overall floating in the front, back, up and down, and left and right directions when docked with the socket connector, The lens is connected to the socket connector by floating, and the plug connector is provided on the outer side of the lens to provide a mating hole for facilitating the docking of the socket connector, and the socket connector is provided with a pair of mating holes The post is indirectly guided by the mating hole and the mating post to directly contact the lens on the plug connector and the lens on the socket connector, but the mating hole of the plug connector and the lens need to be borrowed during manufacture The sockets and the lenses of the socket connector are separately processed by a reference, and each part is processed with a certain error, and the entire plug connector and the socket are accumulated. The component error of the connector is large, so the mutual positional requirements between the lenses are high during processing, the manufacturing precision of the parts is high, and the cost is relatively high.

Therefore, it is necessary to modify the conventional plug connector and the socket connector to overcome the above drawbacks.

The purpose of the present invention is to provide a plug connector and a socket connector that can ensure reliable connection of the first optical fiber and the second optical fiber.

In order to achieve the above object, the present invention adopts the following technical solution: a plug connector for abutting with a socket connector, the plug connector comprising a first insulative housing and a first receiving space formed in the first insulating body a first lens mounted in the first receiving space and a first optical fiber disposed in the first lens, the first optical fiber extending out of the first insulating body, the first lens being mounted on the rear end of the first receiving space a first fixing portion and a plurality of first main body portions extending forward from the first fixing portion into the receiving space, each of the first main body portions including a first abutting portion located at a front end to interface with the socket connector, The plurality of first abutting portions are spaced apart from each other and are relatively movable within the first receiving space.

The purpose of the present invention can also be achieved by the following technical solution: a socket connector that is opposite to the plug connector described in the foregoing technical solution, comprising: a second insulating body, a second formed in the second insulating body Containing space, installed in the second shelter a second lens for optical signal transmission and a plurality of second optical fibers mounted in the second lens opposite to the first optical fiber, the second optical fiber extending out of the second insulating body, the second lens The second body portion includes a second docking pole that protrudes forwardly from the front end of the second body portion and is opposite to the first docking portion. The plurality of second docking posts are spaced apart from each other. The second docking pole is stationary in the second receiving space, and the positions of the plurality of second docking poles are in one-to-one correspondence with the first docking portion.

Compared with the prior art, the authoring connector can be moved by the first butting portions being spaced apart from each other and the first docking portion can be moved in the surrounding space, when the plug connector and the socket connector are docked, by the first The relative movement of the docking parts enables each fiber channel to be automatically aligned, which relaxes the positional requirements of the plug connector and the socket connector when docking, reduces the manufacturing precision of the zero component, improves the yield and transmission reliability, and reduces the cost. .

100‧‧‧ plug connector

11‧‧‧First Insulation Body

111‧‧‧First top wall

1111‧‧‧The first place slot

1112‧‧‧First Pressure Department

112‧‧‧ first bottom wall

1121‧‧‧Second handicap slot

1122‧‧‧Second pressure department

113‧‧‧First side wall

1131‧‧ ‧ gap

114‧‧‧First containment space

12‧‧‧First fiber optic device

120‧‧‧first lens

121‧‧‧First Fixed Department

1210‧‧‧ front surface

122‧‧‧ First main body

1220‧‧‧ first plane

1221‧‧‧ first base

1222‧‧‧First docking department

1223‧‧‧First docking hole

1224‧‧‧ escape trough

1225‧‧‧First cone structure

123‧‧‧First fiber

1231‧‧‧First contact

1232‧‧‧First connection

124‧‧‧First slot

200‧‧‧ socket connector

21‧‧‧Second insulation body

211‧‧‧ second top wall

212‧‧‧ second bottom wall

213‧‧‧ second side wall

214‧‧‧Second containment space

215‧‧‧second rear end face

216‧‧‧second front end face

2161‧‧‧Resist the wall

22‧‧‧second fiber optic device

220‧‧‧second lens

221‧‧‧Second Main Body

2211‧‧‧ Body Department

2212‧‧‧Flexible arm

2213‧‧‧ Reserved slot

2214‧‧‧Card block

222‧‧‧Second docking post

2221‧‧‧Second tapered structure

223‧‧‧second fiber

2231‧‧‧Second contact

2232‧‧‧Second connection

224‧‧‧Second docking hole

23‧‧‧Second shielding shell

The first figure is a schematic diagram of the original plug connector and the socket connector before assembly.

The second figure is a schematic view of the plug connector and the socket connector at the other angle before assembly in the first figure.

The third figure is a schematic view of the first fiber optic device and the second fiber optic device before assembly.

The fourth figure is an exploded perspective view of the plug connector of the present invention.

The fifth figure is an exploded perspective view of another angle of the plug connector in the fourth figure.

The sixth figure is an exploded perspective view of the present socket connector.

The seventh figure is an exploded perspective view of another angle of the socket connector in the sixth figure.

Referring to the first to third figures, the plug connector 100 and the receptacle connector 200 of the present invention are butted against each other. In the present embodiment, the insertion direction of the plug connector 100 or the receptacle connector 200 is the front-rear direction, and the insertion direction of the vertical plug connector 100 or the receptacle connector 200 is the left-right direction.

Referring to the fourth to fifth embodiments, the plug connector 100 includes a first insulative housing 11 and a first optical fiber device 12 mounted in the first insulative housing 11 for optical signal transmission. The first insulative housing 11 has a substantially hollow rectangular parallelepiped structure, and the first insulative housing 11 includes a first top wall 111 at an upper end, a first bottom wall 112 at a lower end and corresponding to the first top wall 111, and The first sidewalls 113 of the first top wall 111 and the first bottom wall 112 are connected. The first top wall 111 , the first bottom wall 112 , and the first side walls 113 together define a first receiving space 114 for receiving the first optical fiber device 12 . The front end of each of the first side walls 113 is recessed inwardly with a notch 1131. The notch 1131 is configured to cooperate with a corresponding structure on the socket connector 200 to achieve a connection between the plug connector 100 and the socket connector 200. Accurate and stable docking.

When the first insulative housing 11 is viewed from the side, the height gradually increases from the back to the front, and the corresponding first receiving space 114 gradually becomes larger from the back to the front. The rear end of the first top wall 111 is provided with four upwardly recessed first retaining grooves 1111 arranged in the left-right direction and a first pressing portion 1112 formed between the adjacent two first retaining grooves 1111. . The rear end of the first bottom wall 112 is provided with four downwardly recessed second retaining grooves 1121 arranged in the left-right direction and a second pressing portion formed between the adjacent two second retaining grooves 1121. 1122. The space formed between the first retaining groove 1111 and the second retaining groove 1121 is to reserve sufficient installation space for the first docking portion 1222 (described in detail later) because The height of the first abutting portion 1222 is greater than the vertical distance between the first pressing portion 1112 and the second pressing portion 1122, and the first retaining groove 1111 and the second retaining groove are disposed. 1121, the first docking portion 1222 is provided with sufficient installation space without affecting the normal positioning of the first fixing portion 121 (described in detail later), and the purpose of escaping is achieved, thereby saving manufacturing costs.

The first fiber optic device 12 includes a first lens 120 and a first optical fiber 123 disposed in the first lens 120. The first optical fiber 123 extends rearwardly out of the first insulative housing 11 . In the embodiment, the first lens 120 is made of transparent plastic, and the first optical fiber 123 is positioned in the first lens 120 by using glue. The first lens 120 includes a first fixing portion 121 having a rectangular parallelepiped shape and a plurality of first main body portions 122 projecting forward from the front end of the first fixing portion 121 to the first fixing portion 121 . The first fixing portion 121 is provided on the front end front surface 1210, and the first main body portion 122 is formed to extend forward from the front surface 1210. The first lens 120 is mounted to the first insulative housing 11 from the front to the rear. The first fixing portion 121 is mounted on the rear of the first insulative housing 11 and is respectively opposite to the first pressing portion 1112 and the second in the up and down direction. The pressing portion 1122 is pressed against to fix the first lens 120. The first main body portion 122 extends from the first fixing portion 121 into the first receiving space 114 and is received in the first receiving space 114 . In this embodiment, the first main body portion 122 includes four. Of course, in other embodiments, the number of the first main body portions 122 may be set according to specific needs. The first main body portion 122 includes a first base portion 1221 extending forward from the front surface 1210, a first abutting portion 1222 extending further forward from the first base portion 1221, and simultaneously penetrating the first base portion 1221 and the first butt joint. The first docking hole 1223 of the portion 1222. The first docking hole 1223 also penetrates the first fixing portion 121 backward. The first optical fiber 123 is located behind the first abutting portion 1222 to be in contact with the first abutting portion 1222. A portion of the first optical fiber 123 at the front end is received in the first docking hole 1223, and another portion of the rear end is located in the rear end. The first fixing portion 121 is extended to be connected to other components.

The original shape of the first abutting portion 1222 is a circular shape. In this embodiment, between the two first butting portions 1222 and between the outermost two first butting portions 1222 and the first insulating body 11 A sufficient amount of movement space is reserved for the first abutting portion 1222, so that the curved faces on both sides of the first abutting portion 1222 are cut into a first plane 1220 suitable for the size of the product. The first plane 1220 extends in the vertical direction. In the embodiment, the first butt joint 1222 is larger in the left and right direction and the up and down direction than the first base portion 1221 because the first mating portion 1222 needs to be secured with the socket connector. The positional accuracy of the 200 docking, the size is too small, the gap between the first mating portions 1222 is too large, which is not conducive to the automatic alignment of each fiber channel; and the first base portion 1221 is installed inside the first receiving space 114, itself The positional accuracy is not excessively required, so that the size of the first base portion 1221 is set smaller than the first butting portion 1222 under the premise of ensuring the strength to save material and save manufacturing cost.

The first base portion 1221 extends forward from the front surface 1210 with a section of the escape groove 1224. The escape groove 1224 penetrates the first base portion 1221 in the left-right direction, but does not penetrate the first base portion 1221 in the up-and-down direction. The escape chute 1224 extends from the front surface of the first fixing portion 121 to the middle of the first base portion 1221, for example, to be arranged, so that the rigidity requirement of the basic function of the first base portion 1221 is satisfied, and the relative increase is relatively increased. The elasticity of the first base portion 1221 facilitates deformation of the first base portion 1221 when the socket connector 200 is mated with the plug connector 100, thereby making the first butt portion 1222 more susceptible to deformation, and at the same time achieving the purpose of escaping, saving manufacturing. cost.

The first lens 120 of the plug connector 100 is a fixed and separated structure, that is, the first fixing portion 121 of the first lens 120 is fixed to the insulative housing, and the first mating portion 1222 is docked with the socket connector 200. Relatively spaced and first docking When the socket 22 is inserted into the socket connector 200, movement can be generated in the up and down and left and right directions. If the first lens 120 is processed by a reference, the first butting portions 1222 that are butted against the socket connector 200 are spaced apart from each other, so that the first butting portion 1222 can be moved up and down, left and right. The upper movement automatically aligns each of the fiber channels by the movement of the first abutting portion 1222, which relaxes the positional requirements of the plug connector 100 when docked with the socket connector 200, reduces the manufacturing precision of the zero components, and improves the goodness. Rate and transmission reliability reduce manufacturing costs. In this embodiment, the fiber channel of the plug connector 100 refers to the path of the optical signal along the path of the first fiber 123, and the fiber channel of the socket connector 200 refers to the path of the optical signal along the path of the second fiber 223. When the plug connector 100 is in contact with the socket connector 200, the two sets of fiber channels are aligned with each other to complete optical signal transmission between each other. The first main body portions 122 are arranged in a row at equal intervals in the left-right direction, and a first spacing groove 124 is disposed between the two adjacent first main body portions 122. The first spacing groove 124 is a motion space reserved for the first body portion 122.

The first abutting portion 1222 has a first tapered hole structure 1225 which is larger in front and rearward in the insertion direction of the socket connector 200, because the second docking pole 222 in the socket connector 200 is also detailed (for details) The tapered structure facilitates the docking of the second docking post 222 of the receptacle connector 200 with the first body portion 122 and relaxes between the first docking holes 1223 of the first body portion 122. The relative position requirement also relaxes the positional requirement between the first butt hole 1223 and the second docking pole 222 of the socket connector 200, which reduces the manufacturing cost of the parts and improves the yield and the transmission reliability. The first optical fiber 123 includes a first contact portion 1231 opposite to the socket connector 200 at the front end, and a first connection portion 1232 located at a rear end of the first contact portion 1231 and connected to the first contact portion 1231. A connecting portion 1232 extends rearward to connect with other components such as a photoelectric conversion module on the main board.

Referring to the sixth to seventh embodiments, the socket connector 200 includes a second insulative housing 21, a second optical fiber device 22 for optical signal transmission installed in the second insulative housing 21, and a cladding portion. The second shielding shell 23 of the second insulating body 21. The second insulative housing 21 has a substantially hollow rectangular parallelepiped structure. The second insulative housing 21 includes a second top wall 211 at an upper end and a second bottom wall 212 at a lower end and corresponding to the second top wall 211. And two second sidewalls 213 connecting the second top wall 211 and the second bottom wall 212. The second top wall 211 , the second bottom wall 212 , and the second side walls 213 together define a second receiving space 214 for receiving the second optical fiber device 22 . The second insulative housing 21 further includes a second rear end surface 215 at the rear end and a second front end surface 216 at the front end. The second front end surface 216 is provided with a pressing wall 2161 which is closed to the second top wall 211, the second bottom wall 212 and the second side wall 213, and the pressing wall 2161 is used for the second The shield case 23 is pressed against. The second receiving space 214 extends through the second rear end surface 215 and penetrates the second front end surface 216 forward. Each of the second side wall 213 and the second top wall 211 is provided with a stepped structure to cooperate with the notch 1131 of the plug connector 100 to achieve a stable docking between the plug connector 100 and the socket connector 200.

The second fiber optic device 22 is a transparent plastic, and the second fiber optic device 22 includes a second lens 220 and a plurality of second fibers 223 mounted in the second lens to cooperate with the first fiber 123. The second optical fiber 223 extends rearwardly out of the second insulative housing 21 . In the embodiment, the second optical fiber 223 is positioned in the second lens 220 by using glue. The second lens 220 includes a second body portion 221 , a second docking pole 222 that is opposite to the first body portion 122 and protrudes forward from the front end of the second body portion 221 . The second body portion 221 extends forwardly through the second docking hole 224 of the second docking pole 222. The second body portion 221 includes a central portion 2211 in the middle, a resilient arm 2212 on both sides of the body portion 2211, and a body portion formed on the body portion A reserved groove 2213 is defined between the 2211 and the resilient arm 2212. The extending end of the elastic arm 2212 is provided with a holding block 2214. The holding block 2214 is pressed against the second rear end surface 215 after the second main body portion 221 is mounted to the second insulating body 21. The width of the two elastic arms 2212 in the left-right direction is greater than the width of the second receiving space 214 in the left-right direction. When the second body portion 221 is just assembled into the second receiving space 214, the elastic arm 2212 Inwardly deformed, the reserved groove 2213 provides a suitable deformation space for the elastic arm 2212. After the second main body portion 221 is completely assembled into the second receiving space 214, the elastic arm 2212 is deformed outwardly. The force applies a certain pressure to the second insulative housing 21 to achieve a stable assembly between the second main body portion 221 and the second insulative housing 21.

The second optical fiber 223 is partially received in the second docking hole 224, and the other portion extends rearwardly out of the second body portion 221. The plurality of second docking posts 222 are spaced apart from each other. The second docking poles 222 are stationary in the second receiving space 214 , and the plurality of second docking poles 222 are in one-to-one correspondence with the first body portion 122 . The second docking posts 222 are arranged in a row at equal intervals in the left and right direction. The plurality of second docking posts 222 are fixed and integral, that is, the plurality of second body portions 221 are fixed in the second insulative housing 21, and the second docking posts 222 are fixed in the socket connector 200. The second docking posts 222 do not interact with each other. The extended end of the second docking pole 222 is provided with a second tapered structure 2221 which gradually becomes larger from the front to rear radius. The present plug connector 100 and the receptacle connector 200 are mated by using the first tapered hole structure 1225 of the plug connector 100 to be in contact with the second tapered structure 2221 of the receptacle connector 200, thereby relaxing the plug connection. The positional requirement of the device 100 when docked with the socket connector 200 reduces the manufacturing precision of the zero component, improves the yield and transmission reliability, and reduces the manufacturing cost; and, compared with the prior art, the original plug connector 100 and socket connector 200 cleverly set the butted components to a cone The first lens 120 and the second lens 220 can be guided to each other by using a tapered structure of the first lens 120 and the second lens 220, without the need for an additional matching hole and the like as in the prior art. The docking post guides the lens of the plug connector to the lens of the socket connector, which simplifies the structure of the connector and saves manufacturing costs.

The second optical fiber 223 includes a second contact portion 2231 opposite to the plug connector 100 at the front end, and a second connecting portion 2232 located at the rear end of the second contact portion 2231 and connected to the second contact portion 2231. The two connecting portions 2232 extend rearward to connect with other components such as a photoelectric conversion module on the main board. The second shielding shell 23 is forwardly pressed against the back of the pressing wall 2161. The second shielding shell 23 includes a top surface 231, a bottom surface 232, and two side surfaces 233 connecting the top surface 231 and the bottom surface 232. The second shielding case 23 is mounted on the second insulative housing 21 from the rear to the front.

Taking the plug connector 100 as an example, the optical transmission principle of the plug connector 100 is: first, the photoelectric signal is converted into a dispersed optical signal by the photoelectric conversion module on the main board; then the dispersed optical signal is in the fiber channel. The optical fiber is transmitted into the lens, and a convex lens is disposed in front of the lens, and the dispersed optical signal is refracted into parallel light by the convex lens or the dispersed optical signal is refracted to focus together to focus the light; finally, the fiber channel of the plug connector 100 After being aligned with the fiber channel of the receptacle connector 200, the converted parallel or focused light will interface with the optical signal obtained by the same principle in the receptacle connector 200.

The first plug 120 is fixed to the fixed structure, that is, the first fixing portion 121 of the first lens 120 is fixed to the insulative housing, and the first mating portion is docked with the receptacle connector 200. The 1222 is relatively spaced and the first docking portion 1222 can be moved in the up and down and left and right directions when the socket connector 200 is inserted. If the arrangement is performed, the first lens 120 is not required to be processed by a reference. The first abutting portions 1222 that are to be mated with the socket connector 200 are spaced apart from each other such that the first butting portions 1222 are movable in the up and down and left and right directions, and the movement of the first butting portion 1222 causes each fiber channel to be automatically paired. Precisely, the positional requirements of the plug connector 100 and the receptacle connector 200 are relaxed, the manufacturing precision of the zero component is reduced, the yield and transmission reliability are improved, and the manufacturing cost is reduced.

The present plug connector 100 and the receptacle connector 200 are mated by using the first tapered hole structure 1225 of the plug connector 100 to be in contact with the second tapered structure 2221 of the receptacle connector 200, thereby relaxing the plug connection. The positional requirement of the device 100 when docked with the socket connector 200 reduces the manufacturing precision of the zero component, improves the yield and transmission reliability, and reduces the manufacturing cost; and, compared with the prior art, the original plug connector The socket connector 200 and the socket connector 200 are ingeniously arranged to have a tapered structure. The first lens 120 and the second lens 220 can be used to guide the first lens 120 and the second lens 220 to each other without the like. As is known in the art, the lens of the plug connector is docked with the lens of the socket connector by additionally providing the docking hole and the docking pole, which simplifies the structure of the connector and saves manufacturing costs.

In summary, the creation meets the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiments, and those who are familiar with the skill of the present invention are equivalent to the equivalent modifications or changes made by the spirit of the present creation. It should be covered by the following patent application.

12‧‧‧First fiber optic device

121‧‧‧First Fixed Department

122‧‧‧ First main body

1220‧‧‧ first plane

1221‧‧‧ first base

1222‧‧‧First docking department

1223‧‧‧First docking hole

1224‧‧‧ escape trough

1225‧‧‧First cone structure

123‧‧‧First fiber

124‧‧‧First slot

22‧‧‧second fiber optic device

221‧‧‧Second Main Body

2211‧‧‧ Body Department

2212‧‧‧Flexible arm

2213‧‧‧ Reserved slot

2214‧‧‧Card block

222‧‧‧Second docking post

223‧‧‧second fiber

Claims (10)

A plug connector for aligning with a socket connector, the plug connector comprising: a first insulative housing; the first receiving space is formed on the first insulative housing; the first lens is mounted on the first The first lens includes a first fixing portion installed at a rear end of the first receiving space and a plurality of first main body portions extending forward from the first fixing portion into the receiving space, wherein the first fixing portion is provided There is a front surface at the front end, each of the first body portions including a first base extending forwardly from the front surface, a first abutment extending further forward from the first base and located at the front end to interface with the receptacle connector, and simultaneously a plurality of first butting portions are disposed at a distance from each other and are relatively movable in the first receiving space; and the first optical fiber is disposed on the first lens The first optical fiber extends out of the first insulative body. The plug connector of claim 1, wherein the first body portions are arranged in a row at equal intervals in the left-right direction. The plug connector of claim 1, wherein the first end of each of the first abutting portions has a first tapered hole structure whose radius gradually decreases along a insertion direction of the socket connector, and the first optical fiber is located Inside the first cone. The plug connector of claim 1, wherein the first abutting portion is connected to the first base portion and located at a front end of the first base portion, and the first butt hole extends through the first fixing portion. The plug connector of claim 4, wherein the first base portion has a smaller dimension in the left-right direction and the up-and-down direction than the first mating portion. The plug connector of claim 4, wherein the first base extends forwardly from the front surface with a section of the escape slot, the escape slot extending through the first base in the left-right direction, but The lower part does not penetrate the first base. The plug connector of claim 4, wherein the first and second sides of each of the first abutting portions are provided with a first plane extending in the up and down direction, and the adjacent two first butting portions are disposed between There is a first spacing groove for the movement of the first docking portion. The plug connector of claim 1, wherein the first insulative housing comprises a first top wall above the first receiving space and a first side opposite the first top wall and located below the first receiving space a bottom wall, a rear end of the first top wall is provided with a first retaining groove spaced apart in the left-right direction, and a first pressing portion formed between the adjacent two first retaining grooves, the first The rear end of the bottom wall is provided with a second retaining groove which is arranged in the left-right direction and has a position corresponding to the first retaining groove, and is formed between the adjacent two second retaining grooves and is at the position and the first pressing a first pressing portion corresponding to the first one, a space between the first retaining groove and the second retaining groove for receiving the first abutting portion, wherein the first pressing portion and the second pressing portion are The first fixing portion is pressed against the first fixing portion in the up and down direction to position the first fixing portion. A socket connector that is opposite to the plug connector described in claim 1 and includes a second insulative housing; the second receiving space is formed on the second insulative housing; and the second lens is mounted on The second lens includes a second body portion, and the plurality of second body portions protrude forwardly from the front end of the second body portion and the first body portion is opposite to the first docking portion. a second docking pole, the plurality of second docking poles are spaced apart from each other, the second docking pole is stationary in the second receiving space, and the positions of the plurality of second docking poles are in one-to-one correspondence with the first docking portion; And a plurality of second optical fibers are mounted in the second lens, the second optical fibers are opposite to the first optical fibers and extend out of the second insulating body. The socket connector of claim 9, wherein the second body portion is located a central body portion, a resilient arm on both sides of the body portion, and a reserved groove formed between the body portion and the elastic arm, wherein a width in a lateral direction between the two elastic arms is larger than a width in a lateral direction of the second receiving space The extending end of the elastic arm is provided with a holding block, and the holding block is clamped to the rear end of the second insulating body after the second main body portion is mounted to the second insulating body.