CN108614328B

CN108614328B - Optical fiber connector capable of changing butt joint polarity

Info

Publication number: CN108614328B
Application number: CN201611140066.6A
Authority: CN
Inventors: 林雨晴
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-12-12
Filing date: 2016-12-12
Publication date: 2021-12-31
Anticipated expiration: 2036-12-12
Also published as: CN108614328A

Abstract

The optical fiber connector comprises a hollow inner shell, a hollow first outer shell and a hollow second outer shell. The inner shell is provided with a first wall, a second wall, a third wall and a fourth wall, wherein the first wall is opposite to the third wall and is connected with the second wall and the fourth wall. The first outer housing fits over the inner housing and the second outer housing fits over the inner housing and engages the first outer housing. A feature cantilever arm extends from the second outer housing and can be disposed on the first wall or the third wall of the inner housing. The feature cantilever is insertable into the feature groove of the fiber optic adapter when the inner housing is inserted into the fiber optic adapter.

Description

Optical fiber connector capable of changing butt joint polarity

Technical Field

The present invention relates to optical fiber connectors, and more particularly, to an optical fiber connector with changeable mating polarity.

Background

Fiber optic connectors are a common component in fiber optic communication systems. For example, a fiber optic connector may connect a short length of optical fiber to a longer length of optical fiber, may connect an optical fiber to an active component, such as a light source or detector, or may connect an optical fiber to a passive component, such as an optical switch or attenuator. The primary function of the fiber optic connector is to align the core of the optical fiber with the optical path of the mating component. In this way, the light beam in the optical fiber will be couplable to the optical path of the docking assembly.

Referring to fig. 1a and 1b, a conventional male MPO type optical fiber connector 100a and a female MPO type optical fiber connector 100b are respectively shown. The top surface 110 of the front section of the fiber

optic connectors

100a and 100b is formed with an elongated feature 112, and the two sides of the front section are formed with recesses 114. The

optical fiber connectors

100a and 100b have a plurality of optical fibers 130 exposed at the front end 120 thereof, wherein the end of each optical fiber 130 is flush with the end 120 of the

optical fiber connectors

100a and 100 b. In addition, two guiding holes 150 are formed on the end face 120 of the optical fiber connector 100b, and a pair of guiding pins 140 are extended from the end face 120 of the optical fiber connector 100a and can be inserted into the guiding holes 150 respectively.

In order to allow the optical fiber connector 100a to be mated with the optical fiber connector 100b, a fiber adapter of the same type is required. Referring to fig. 2, a conventional MPO type fiber optic adapter 200 is shown. The conventional MPO type fiber adapter 200 is a hollow structure having openings 210 at both ends for inserting the

fiber connectors

100a and 100b, respectively. In order to allow the

optical fiber connectors

100a and 100b to be firmly connected to the optical fiber adapter 200, a pair of hooks 220 are disposed at each opening 210. In addition, a feature groove 230 is provided on the inner wall at each opening 210 for receiving the feature protrusion 112 of the

optical fiber connector

100a, 100 b.

When the

optical fiber connectors

100a and 100b are inserted into the optical fiber adapter 200 from the opening 210, the hooks 220 of the optical fiber adapter 200 are hooked on the concave portions 114 of the

optical fiber connectors

100a and 100b, respectively, so that the

optical fiber connectors

100a and 100b and the optical fiber adapter 200 can be stably connected, the guide pins 140 of the optical fiber connector 100a are inserted into the guide holes 150 of the optical fiber connector 100b, and the optical fibers 130 exposed at the front ends of the two

optical fiber connectors

100a and 100b are contacted, respectively, thereby achieving the purpose of optical fiber connection.

The feature recess 230 of the fiber optic adapter 200 is configured to receive the feature protrusion 112 of the fiber

optic connector

100a, 100b such that the fiber

optic connector

100a, 100b can be inserted into the fiber optic adapter 200 in only one predetermined orientation. Taking fig. 2 as an example, when the characteristic protrusion 112 of the

optical fiber connectors

100a and 100b shown in fig. 1a or 1b is upward, the optical fiber adapter 200 cannot be inserted from the opening 210; and may be inserted into the fiber optic adapter 200 when the fiber

optic connectors

100a, 100b are rotated so that their feature protrusions 112 face downward. Thus, the feature protrusions 112 on the fiber

optic connectors

100a, 100b mate with the feature grooves 230 on the fiber optic adapter 200, limiting the ability of the fiber

optic connectors

100a, 100b to mate with opposing fiber optic connectors only with a predetermined polarity (polarity).

However, most of the existing

optical fiber connectors

100a or 100b cannot change the position of the feature protrusion 112, and therefore cannot adjust the polarity of the connection.

In view of the above, a solution to the above problem needs to be provided.

Disclosure of Invention

The present invention provides an optical fiber connector with changeable mating polarity.

To achieve the above object, the optical fiber connector of the present invention includes a hollow inner housing, a hollow first outer housing, and a hollow second outer housing. The inner shell is provided with a first wall, a second wall, a third wall and a fourth wall, wherein the first wall is opposite to the third wall and is connected with the second wall and the fourth wall. The first outer shell is sleeved on the inner shell and provided with a fifth wall, a sixth wall, a seventh wall and an eighth wall, and the fifth wall is opposite to the seventh wall and is connected with the sixth wall and the eighth wall. The second outer housing fits over the inner housing and engages the first outer housing. The second outer shell is provided with a ninth wall, a tenth wall, an eleventh wall and a twelfth wall, wherein the ninth wall is opposite to the eleventh wall and is connected with the tenth wall and the twelfth wall. The second housing also includes a feature cantilever connected to the ninth wall. The second outer housing can be nested over the inner housing with the feature cantilever arm disposed on the first wall or the third wall and the feature cantilever arm can be inserted into the feature groove of the fiber optic adapter when the inner housing is inserted into the fiber optic adapter.

In order to make the aforementioned and other objects, features, and advantages of the present invention more apparent, embodiments of the present invention are described below in detail in conjunction with the accompanying drawings.

Drawings

Fig. 1a is a perspective view of a conventional male MPO type optical fiber connector.

Fig. 1b is a perspective view of a conventional female MPO-type optical fiber connector.

Fig. 2 is a perspective view of a conventional MPO-type fiber optic adapter.

Fig. 3 is an exploded perspective view of the optical fiber connector of the present invention.

Fig. 4a is a perspective view of the tailstock of the optical fiber connector according to the present invention.

FIG. 4b is a side view of the tail block of the optical fiber connector of the present invention.

FIG. 4c is another side view of the tail block of the optical fiber connector of the present invention.

Fig. 5 is a perspective view of a spring of the optical fiber connector of the present invention.

Fig. 6a to 6c are perspective views of the spring seat of the optical fiber connector of the present invention at different viewing angles.

Fig. 7a is a perspective view of the optical fiber ferrule of the optical fiber connector of the present invention.

FIG. 7b is another perspective view of the fiber optic ferrule of the fiber optic connector of the present invention.

Fig. 8a is a perspective view of an inner housing of the fiber optic connector of the present invention.

Fig. 8b is another perspective view of the inner housing of the fiber optic connector of the present invention.

Fig. 9a to 9d are perspective views of the first outer housing of the optical fiber connector of the present invention at different viewing angles.

Fig. 9e to 9h are different side views of the first outer housing of the optical fiber connector of the present invention.

Fig. 10a to 10d are perspective views of the second housing of the optical fiber connector of the present invention at different viewing angles.

Fig. 10e is a side view of the second housing of the fiber optic connector of the present invention.

Fig. 10f is another side view of the second housing of the fiber optic connector of the present invention.

Fig. 11 is a combination diagram of the tail seat, the spring seat, the fiber ferrule, the inner housing and the first outer housing in the optical fiber connector according to the present invention.

Fig. 12 is a cross-sectional view taken along line a-a of fig. 11.

Fig. 13 is a perspective view of the optical fiber connector of the present invention.

Fig. 14 is a sectional view taken along line B-B in fig. 13.

Fig. 15 is a perspective view of an optical fiber connector according to another aspect of the present invention.

Fig. 16 is a cross-sectional view taken along line C-C of fig. 15.

Description of reference numerals:

100a fiber connector 300 fiber connector

Tailstock 10 of 100b optical fiber connector

110 front end of upper surface 11

112 projection 12 flange

114 recess 14 resilient arm

120 end face 15 opening

130 optical fiber 17 engaging protrusion

140 guide pin 20 spring

150 leading end of the hole 21

200 rear end of fiber optic connector 22

210 opening 23 opening

220 hook 30 spring seat

230 feature groove 31 front surface

32 rear surface 612 bottom wall

33 guide pin 613 right wall

34 limiting wall 614 left wall

35 opening 615 chamber

40 fiber casing 617 front opening

41 front end surface 618 rear opening

42 back end 621 engagement/receiving opening

43 opening 622 engaging portion/receiving opening

44 opening 631 stop

46 opening 632 stop

50 inner shell 641 split

511 Top wall 642 slit

512 bottom wall 653 engaging portion

513 right wall 654 engaging portion

514 left wall 661 projection

662 projection of 515 accommodating chamber

516 engage opening 70 second housing body

517 front opening 711 top wall

518 rear opening 712 bottom wall

Right wall of 521 groove 713

522 groove 714 left wall

531 stop 715 chamber

532 stopper 717 front opening

60 first outer housing 718 rear opening

611 top wall 721 engagement portion/projection

722 engaging portion/engaging protrusion 761 notch

741 engages the cantilever 762 notch

742 engaging cantilever 771 feature cantilever

751 pressing projection 781 restricting block

752 pressing protrusion

Detailed Description

Referring to fig. 3, an optical fiber connector 300 of the present invention, for example, an MPO type optical fiber connector, includes a tail block 10, a spring 20, a spring seat 30, a fiber ferrule 40, an inner housing 50, a first outer housing 60, and a second outer housing 70.

Referring to fig. 4a to 4c, the tailstock 10 is integrally formed by plastic injection, and includes a front end 11 and a flange 12. The flange 12 is substantially rectangular in cross-section, and the front end portion 11 extends longitudinally from the flange 12. A pair of resilient arms 14 extend longitudinally from the front end portion 11, the resilient arms 14 being disposed opposite one another. The front end 11 is also formed with an opening 15 between the base portions of the two resilient arms 14, the opening 15 extending longitudinally through the flange 12 to form a through hole. Engaging projections 17 are formed on opposite outer sides of the two resilient arms 14, respectively.

Referring to fig. 5, the spring 20 may be a coil spring (coil spring) having a longitudinal extension, and the spring 20 defines a longitudinally extending opening 23. The spring 20 has a front end 21 and a rear end 22, wherein the rear end 22 is configured to abut against the front end 11 of the tailstock 10, and when the spring 20 contacts the front end 11 of the tailstock 10, the opening 23 of the spring 20 is communicated with the opening 15 of the tailstock 10.

Referring to fig. 6a to 6c, the spring seat 30 is integrally formed by injection molding, and has a substantially rectangular cross section. A pair of guide pins 33 extend longitudinally from the front surface 31 of the spring seat 30, and a pair of restricting walls 34 extend longitudinally from the rear surface 32 of the spring seat 30, the restricting walls 34 being disposed opposite to each other, and the opposing inner side surfaces of the restricting walls and the restricting walls being concave surfaces. Spring seat 30 is also formed with a rectangular opening 35, opening 35 extending longitudinally through front surface 31 to rear surface 32.

Referring to fig. 7a and 7b, the ferrule 40 may be an MT-type multi-fiber ferrule having a substantially rectangular cross-section. The ferrule 40 extends longitudinally in a length direction and has a front end face 41 and an opposite rear end face 42. Two circular openings 44 are formed in the rear end surface 42, and the two openings 44 are respectively inserted by the two guide pins 33 of the spring seat 30. The rear face 42 also defines a rectangular opening 46 between the two openings 44, the opening 46 extending along the length of the ferrule 40 toward the front face 41. The front end face 41 is formed with a plurality of circular openings 43, the openings 43 being aligned and communicating with the opening 46. The opening 46 enables insertion of a ribbon fiber (ribbon fiber), and the end sections of the respective fibers of the ribbon fiber are inserted into the openings 43, respectively.

Referring to fig. 8a and 8b, the inner housing 50 is integrally formed by plastic injection, and has a substantially hollow rectangular parallelepiped shape. The inner housing 50 has a top wall 511, a bottom wall 512, a right wall 513 and a left wall 514, wherein the top wall 511 is opposite to the bottom wall 512 and is connected to the right wall 513 and the left wall 514, and the

walls

511, 512, 513 and 514 together define a longitudinal chamber 515 having two opposite front openings 517 and rear openings 518 in the longitudinal direction, i.e. the front end of the hollow inner housing 50 has an opening 517, and the rear end has an opening 518. The right wall 513 and the left wall 514 are each formed with an engagement opening 516 for engaging with the two engagement projections 17 of the tailstock 10.

Elongated grooves

521, 522, such as dovetail grooves, are formed in the top wall 511 and the bottom wall 512, respectively, and the two

grooves

521, 522 are located correspondingly and extend longitudinally to the front edges of the top wall 511 and the bottom wall 512, respectively. In addition, at least one

stopper

531, 532 is formed on the top wall 511 and the bottom wall 512, and an inclined surface is formed on each of the at least one

stopper

531, 532, and the inclined surface is gradually raised towards the rear end of the top wall 511 and the bottom wall 512, that is, the inclined surface is inclined downwards towards the front end of the top wall 511 and the bottom wall 512. In an embodiment, two stops 531 are provided on the top wall 511 and two stops 532 are provided on the bottom wall 512.

Referring to fig. 9a to 9h, the first outer housing 60 is hollow and is integrally formed by injecting plastic. The first outer housing 60 has a top wall 611, a bottom wall 612, a right wall 613 and a left wall 614, wherein the top wall 611 is opposite to the bottom wall 612 and connected to the right wall 613 and the left wall 614, the

walls

611, 612, 613 and 614 together define a longitudinal chamber 615 having two opposite front openings 617 and rear openings 618 in the longitudinal direction, i.e. the hollow first outer housing 60 has an opening 617 at the front end and an opening 618 at the rear end. The top wall 611 has an engaging portion 621, such as a rectangular receiving opening 621, and the receiving opening 621 is a through hole passing from the outside of the receiving chamber 615 to the inside of the receiving chamber 615. The receiving opening 621 forms a stop 631 toward the front end of the top wall 611, wherein the stop 631 can form a slit 641, and the slit 641 extends to the edge of the front end of the top wall 611 and gradually widens toward the edge of the top wall 611, so that the receiving opening 621 can communicate with the slit 641 to the edge of the top wall 611. Similarly, the bottom wall 612 forms an engaging portion 622, such as a rectangular receiving opening 622, and the receiving opening 622 is a through hole passing from the outside of the chamber 615 to the inside of the chamber 615. The receiving opening 622 forms a stop 632 forward of the front end of the bottom wall 612, wherein the stop 632 can form a slit 642, and the slit 642 extends to the edge of the front end of the bottom wall 612 and gradually widens toward the edge of the bottom wall 612, so that the receiving opening 622 can be communicated to the edge of the bottom wall 612 through the slit 642. Further, engaging

portions

653, 654 are formed on the right wall 613 and the left wall 614, respectively, wherein the engaging

portions

653, 654 can be protrusions or recesses, or a combination of both.

Projections

661, 662 are formed on the top wall 611 and the bottom wall 612, respectively, within the chamber 615.

Referring to fig. 10a to 10f, the second housing 70 is a hollow structure and is integrally formed by injecting plastic. The second housing 70 has a top wall 711, a bottom wall 712, a right wall 713 and a left wall 714, wherein the top wall 711 is opposite to the bottom wall 712 and is connected to the right wall 713 and the left wall 714, and the

walls

711, 712, 713 and 714 together define a longitudinal chamber 715, which has two opposite front openings 717 and back openings 718 in the longitudinal direction, that is, the hollow second housing 70 has an opening 717 at the front end and an opening 718 at the back end. A rectangular notch 761 is formed in the top wall 711, and an engaging arm 741 having elasticity in the longitudinal direction extends rearward from the top wall 711 inside the notch 761 and extends out of the notch 761. An engaging portion 721, for example, an engaging protrusion 721 is formed on an outer side surface of an end of the engaging cantilever 741, and the engaging protrusion 721 can be placed in the receiving opening 621 of the first outer housing 60, that is, the engaging portion 721 of the second outer housing 70 can be engaged with the engaging portion 621 of the first outer housing 60. The engaging protrusion 721 can also be placed in the receiving opening 622 so that the engaging portion 721 can be engaged with the engaging portion 622. The engaging protrusion 721 is formed with a slope which is gradually inclined downward toward the end of the engaging cantilever 741. In addition, a pressing projection 751 is formed on an outer side surface of the engaging cantilever 741, the pressing projection 751 is substantially trapezoidal and is connected to the engaging projection 721, and the pressing projection 751 is tapered toward the engaging projection 721, wherein the

slits

641 and 642 of the first outer housing 60 can receive a part of the pressing projection 751. A rectangular notch 762 is formed in the bottom wall 712, and a longitudinally extending resilient engaging arm 742 extends rearwardly from the bottom wall 712 inwardly of the notch 762 and out of the notch 762. An engaging portion 722, such as an engaging projection 722, is formed on an outer side surface of the end of the engaging cantilever 742, and the engaging projection 722 can be placed in the receiving opening 622 of the first outer case 60, that is, the engaging portion 722 of the second outer case 70 can be engaged with the engaging portion 622 of the first outer case 60. The engaging protrusion 722 can also be placed in the receiving opening 621 so that the engaging portion 722 can engage with the engaging portion 621. The engaging protrusion 722 is formed with a slope which gradually slopes downward toward the end of the engaging cantilever 742. In addition, a pressing protrusion 752 is further formed on an outer side surface of the engaging cantilever 742, the pressing protrusion 752 having a substantially trapezoidal shape and being connected to the engaging protrusion 722, the pressing protrusion 752 being tapered toward the engaging protrusion 722, wherein the

slits

641 and 642 of the first outer case 60 can receive a part of the pressing protrusion 752. An elongated cantilever feature 771 also extends from the top wall 711, the cantilever feature 771 running longitudinally and being positioned opposite the engagement cantilever 741 so as to extend forwardly from the top wall 711. The inside surface of the feature arm 771 is formed with a restricting piece 781 which can be inserted into the

groove

521 or 522 on the outside surface of the inner case 50 from the front end of the inner case 50, that is, from the front end of the

groove

521, 522, and the restricting piece 781 can only be longitudinally moved in the

groove

521, 522 and cannot be directly removed from above the

groove

521, 522. Further, engaging

portions

753, 754 are formed on the right wall 713 and the left wall 714, respectively, wherein the engaging

portions

753, 754 can be protrusions or recesses, or a combination of both. The engaging

portions

753, 754 have shapes corresponding to the shapes of the engaging

portions

653, 654 of the first outer case 60, respectively, and can be engaged with each other. The engaging

portions

753, 754 also have shapes corresponding to the shapes of the engaging

portions

654, 653 of the first housing body 60, respectively, and can be engaged with each other.

Referring to fig. 11 and 12, in the optical fiber connector 300 according to the present invention, the front end surface of the front end portion 11 of the tailstock 10 contacts the rear end surface of the inner housing 50, the elastic arms 14 are inserted into the accommodating chamber 515 of the inner housing 50 from the rear opening 518, and the engaging protrusions 17 on the elastic arms 14 are engaged with the engaging openings 516, respectively. The front end 11 of the tailstock 10 abuts against the rear end 22 of the spring 20 and pushes the spring 20 toward the spring seat 30, pressing the front end 21 of the spring 20 against the rear surface 32 of the spring seat 30. The guide pins 33 of the spring seat 30 are inserted into the openings 44 on the rear end face 42 of the fiber optic ferrule 40, respectively. The ferrule 40 is pushed into the inner housing 50 by the spring 20, and the front end face 41 of the ferrule 40 is pushed out of the inner housing 50. Further, the front end of inner housing 50 is inserted into compartment 615 of first outer housing 60 from rear opening 618. During insertion, the

tabs

661, 662 on the top and

bottom walls

611, 612 of the first outer housing 60 slide over the ramps on the

stops

531, 532 on the top and

bottom walls

511, 512, respectively, of the inner housing 50 and eventually over the

stops

531, 532. After the inner housing 50 is inserted into the first outer housing 60, the top wall 511 and the bottom wall 512 of the inner housing 50 directly face the top wall 611 and the bottom wall 612 of the first outer housing 60, respectively.

After the first outer housing 60 is fitted over the outer surface of the inner housing 50, the second outer housing 70 is fitted over the outer surface of the inner housing 50 and connected to the first outer housing 60. In detail, referring to fig. 13 and 14, the front end of the inner housing 50 is inserted into the second outer housing 70 from the rear opening 718, and the engaging

portions

721 and 722 of the second outer housing 70 are engaged with the engaging

portions

621 and 622 of the first outer housing 60, respectively, and the engaging

portions

753 and 754 are engaged with the engaging

portions

653 and 654, respectively. The method of engaging the engaging portion 721 with the engaging portion 621 is to press down the pressing projection 751 to press down the engaging portion 721 toward the inner case 50 in the process of approaching the second outer case 70 to the first outer case 60. Similarly, the engaging portion 722 is engaged with the engaging portion 622 by depressing the pressing projection 752 to press the engaging portion 722 toward the inner case 50 in the process of approaching the second outer case 70 to the first outer case 60. Since the engagement cantilever 741 of the second outer housing 70 and the stopper 631 of the first outer housing 60 are spaced apart from the top wall 511 of the inner housing 50, and the engagement cantilever 742 and the stopper 632 are also spaced apart from the bottom wall 512 of the inner housing 50, the engagement portion 721 can slide on the bottom of the stopper 631 and pass over the stopper 631. Similarly, the engaging portion 722 can slide on the bottom of the stopper 632 and pass over the stopper 632. When the engaging portion 721 passes the stopper 631, the engaging cantilever 741 is sprung up to engage the engaging portion 721 with the engaging portion 621 of the first outer housing 60, that is, to allow the engaging protrusion 721 to be placed in the receiving opening 621. At this time, a portion of the pressing protrusion 751 of the second outer housing 70 is positioned in the slit 641 of the first outer housing 60. Similarly, when the engaging portion 722 passes the stopper 632, the engaging arm 742 is sprung up to engage the engaging portion 722 with the engaging portion 622 of the first outer housing 60, i.e. to place the engaging protrusion 722 in the receiving opening 622. At this time, a portion of the pressing protrusion 752 of the second outer case 70 is positioned in the slit 642 of the first outer case 60. When the engaging

portions

721, 722 are engaged with the engaging

portions

621, 622, respectively, the engaging

portions

753, 754 of the second casing body 70 are also engaged with the engaging

portions

653, 654 of the first casing body 60, respectively. When the second outer housing 70 is connected to the first outer housing 60, the limiting blocks 781 of the second outer housing 70 are inserted from the front end of the groove 521 of the inner housing 50, and the characteristic cantilever 771 is formed as a characteristic protrusion on the top wall 511 of the inner housing 50.

The optical fiber connector 300 according to the present invention, wherein a ribbon-shaped optical fiber (not shown) can pass through the tailstock 10, the spring 20 and the spring seat 30 and be inserted into the optical fiber sleeve 40 from the opening 46. The end segments of the respective optical fibers of the ribbon fiber can be inserted into the openings 43 of the ferrule 40, respectively, with the end faces of the respective optical fiber end segments being flush with the front end face 41 of the ferrule 40. The fiber optic connector 300 of the present invention is capable of being plugged into a fiber optic adapter of the same type, wherein the fiber optic adapter may be a commercially available fiber optic adapter and therefore its structure is not described herein. The fiber optic connector 300 of the present invention is capable of mating with an oppositely positioned fiber optic connector using the same type of fiber optic adapter.

When the fiber optic connector 300 of the present invention is assembled as described above, the characteristic cantilever 771 will become a characteristic protrusion such that the fiber optic connector 300 can only be inserted into a fiber optic adapter of the same type in one predetermined orientation. Referring to the fiber optic adapter 200 shown in fig. 2, when the characteristic arm 771 of the fiber optic connector 300 is facing upward, the fiber optic adapter 200 cannot be inserted from the opening 210, and only when the fiber optic connector 300 is rotated to make the characteristic arm 771 of the fiber optic connector 300 facing downward, the characteristic groove 230 of the fiber optic adapter 200 receives the characteristic arm 771 of the fiber optic connector 300, so that the fiber optic connector 300 can be inserted into the fiber optic adapter 200 from the opening 210. As such, the optical fiber connector 300 is limited to be mated with another optical fiber connector only with a predetermined polarity (polarity).

In order to change the polarity of the optical fiber connector 300, the

pressing protrusions

751, 752 of the second housing 70 may be simultaneously depressed and the second housing 70 may be pulled out. Thereafter, the second outer housing 70 is inverted so that the characteristic cantilever 771 thereof is directed downward and the second outer housing 70 is fitted over the outer surface of the inner housing 50 and connected to the first outer housing 60 in the manner described above. Referring to fig. 15 and 16, after the second housing 70 is connected to the first housing 60, the engaging

portions

721, 722 of the second housing 70 are engaged with the engaging

portions

622, 621 of the first housing 60, respectively, and the engaging

portions

753, 754 are engaged with the engaging

portions

654, 653, respectively. After the engaging portion 721 is engaged with the engaging portion 622, the engaging protrusion 721 is located in the receiving opening 622, and a portion of the pressing protrusion 751 is located in the slit 642; after the engaging portion 722 engages with the engaging portion 621, the engaging protrusion 722 is located in the receiving opening 621, and a portion of the pressing protrusion 752 is located in the gap 641. When the second outer housing 70 is connected to the first outer housing 60, the limiting blocks 781 of the second outer housing 70 are inserted from the front ends of the grooves 522 of the inner housing 50, and the characteristic cantilever 771 is formed as a characteristic protrusion on the bottom wall 512 of the inner housing 50, thereby changing the polarity of the optical fiber connector 300.

According to the optical fiber connector 300 of the present invention, the restricting pieces 781 cannot be directly removed from above the

recesses

521, 522, so that the characteristic cantilever 771 is prevented from lifting up from the top wall 511 or the bottom wall 512 of the inner housing 50. In addition,

stoppers

531 and 532 on top wall 511 and bottom wall 512 of inner housing 50 can prevent movement of

projections

661 and 662 on top wall 611 and bottom wall 612 of first outer housing 60, and thus can prevent first outer housing 60 from being pulled out from the front end of inner housing 50. The

stoppers

631 and 632 in front of the receiving

openings

621 and 622 of the first outer case 60 can prevent the engaging

protrusions

721 or 722 of the second outer case 70 from moving, thereby preventing the engaging

protrusions

721 and 722 from being pulled out of the receiving

openings

621 or 622, and thus preventing the second outer case 70 from being separated from the first outer case 60. If the second housing 70 is separated from the first housing 60 to change the polarity of the optical fiber connector 300, the

pressing protrusions

751 and 752 need only be depressed with a finger, without any tool.

Although the present invention is illustrated with respect to MPO type fiber optic connectors, it will be appreciated by those skilled in the art that the fiber optic connectors according to the present invention may be other types of fiber optic connectors.

Although the present invention has been described with reference to the foregoing embodiments, it should be understood that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A fiber optic connector for insertion into a fiber optic adapter having a feature recess therein, comprising:

the hollow inner shell is provided with a first wall, a second wall, a third wall and a fourth wall, wherein the first wall is opposite to the third wall and is connected with the second wall and the fourth wall;

the hollow first outer shell is sleeved on the inner shell and provided with a fifth wall, a sixth wall, a seventh wall and an eighth wall, and the fifth wall is opposite to the seventh wall and is connected with the sixth wall and the eighth wall; and

a hollow second outer housing fitted over said inner housing, said second outer housing having a ninth wall, a tenth wall, an eleventh wall and a twelfth wall, said ninth wall being opposite said eleventh wall and being connected to said tenth wall and said twelfth wall, said second outer housing further including a cantilever arm characterized as being connected to said ninth wall,

the second outer shell can be sleeved on the inner shell in one of two ways that the characteristic cantilever is arranged on the first wall and the third wall, and when the inner shell is inserted into the optical fiber adapter, the characteristic cantilever can be inserted into the characteristic groove, so that the butt joint polarity is changed;

wherein the first outer housing has a first receiving opening on the fifth wall and a second receiving opening on the seventh wall, the first outer housing further has a first stopper and a second stopper, the first stopper is located in front of the first receiving opening, the first stopper has a first slit formed thereon, the first slit extends to an edge of the front end of the fifth wall and gradually widens toward the edge of the fifth wall, so that the first receiving opening can be communicated with the edge of the fifth wall through the first slit, the second stopper is located in front of the second receiving opening, the second stopper has a second slit formed thereon, the second slit extends to an edge of the front end of the seventh wall and gradually widens toward the edge of the seventh wall, so that the second receiving opening can be communicated with the edge of the seventh wall through the second slit,

the second housing further includes a resilient first engaging cantilever, a first engaging protrusion and a first pressing protrusion, the first engaging protrusion and the first pressing protrusion being fixed to the first engaging cantilever, the first engaging protrusion being selectively engageable with one of the first receiving opening and the second receiving opening, the first pressing protrusion being trapezoidal-shaped and connected to the first engaging protrusion, the first pressing protrusion tapering toward the first engaging protrusion, wherein the first pressing protrusion is pressed by a user to press the first engaging cantilever toward the inner housing, and the first slit and the second slit are capable of receiving a portion of the first pressing protrusion.

2. The fiber optic connector of claim 1, wherein the first and third walls of the inner housing each have a groove formed therein, the second outer housing further including a limiting block disposed on the cantilever arm, the limiting block being capable of being placed in and not being directly removable from over the two grooves.

3. The optical fiber connector according to claim 1, wherein the second housing further comprises a resilient second engaging cantilever and a second engaging projection fixed to the second engaging cantilever, the second engaging projection being engageable with the first receiving opening or the second receiving opening.

4. The fiber optic connector of claim 3, wherein the second outer housing further includes a second press tab formed on the second engagement arm, the second press tab being depressible by a user to press the second engagement arm toward the inner housing.

5. The optical fiber connector according to claim 1, wherein the second outer housing further includes a first engaging portion and a second engaging portion, and the first outer housing further includes a third engaging portion engageable with the first engaging portion or the second engaging portion.

6. The fiber optic connector of claim 1, wherein the inner housing further includes two stops disposed on the first wall and the third wall, respectively, for limiting movement of the first outer housing.

7. The fiber optic connector of claim 1, wherein the fiber optic connector is an MPO-type fiber optic connector.