Patent Publication Number: US-2022221658-A1

Title: Mechanical connection interface

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is being filed on May 14, 2020 as a PCT International Patent Application and claims the benefit of U.S. Patent Application Ser. No. 62/849,760, filed on May 17, 2019, and claims the benefit of U.S. Patent Application Ser. No. 62/891,749, filed on Aug. 26, 2019, and claims the benefit of U.S. Patent Application Ser. No. 62/929,532, filed on Nov. 1, 2019, and claims the benefit of U.S. Patent Application Ser. No. 62/961,044, filed on Jan. 14, 2020, and claims the benefit of U.S. Patent Application Ser. No. 63/003,996, filed on Apr. 2, 2020, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to mechanical connection interfaces. More particularly, the present disclosure relates to turn-to-secure mechanical connection interfaces that may be used with telecommunications connectors. 
     BACKGROUND 
     A turn-to-secure connection interface is an interface that is connected and disconnected by a twisting motion. Turn-to-secure connection interfaces have been used with telecommunications connectors. For example, turn-to-secure connection interfaces have been used for securing telecommunications connectors to one another, for securing telecommunications connectors to telecommunication adapters, and for interconnecting separate pieces of telecommunications connectors. U.S. Pat. No. 7,744,288 and European Patent 2302431 disclose telecommunications connectors utilizing turn-to-secure connection interfaces. 
     SUMMARY 
     Aspects of the present disclosure relate to turn-to-secure connection interfaces for coupling together two components. In one example, the two components can be parts of a telecommunications connection system such as a fiber optic connection system. In certain examples, each of the components can be a part of a telecommunications connector or a telecommunications adapter. In one example, one of the components can include a fiber optic adapter or part of a fiber optic adapter and the other component can include a fiber optic connector or a part of a fiber optic connector. In other examples, the components can be different parts of a fiber optic connector. In still other examples, one of the components can be a dust cap and the other component can be a retention sleeve of a fiber optic connector. 
     In certain examples, components embodying the turn-to-secure interface are rotationally movable about a central axis relative to each other between first and second rotational states. The components can include stop arrangements that limit a range of rotational movement between the first and second rotational states. The stop arrangements can also be configured to allow the components to be axially separated from one another when in the first rotational state, and to prevent the components from being axially separated from one another when in the second rotational state. 
     The components can include a snap-fit arrangement for resisting movement from the second rotational state to the first rotational state. In one example, the snap-fit configuration can be designed such that the snap-fit arrangement is required to be damaged (e.g., broken) for the components to be rotated relative to each other from the second rotational state to the first rotational state. In other examples, the snap-fit configuration may be configured to flex, without breaking or otherwise being damaged, to accommodate movement from the second rotational state to the first rotational state. In certain examples, the components do not move axially relative to one another as the components are rotated between the first and second rotational states. 
     Another aspect of the present disclosure relates to a turn-to-secure connection interface including a first component defining an axis. The first component includes a rotational securement latch. The first component also includes a first stop arrangement including a first stop surface that faces in a first axial direction axis, and a second stop surface that faces in a second axial direction along the axis. The first axial direction is opposite from the second axial direction. The first component also includes a third stop surface that faces in a first rotational direction about the axis. The turn-to-secure connection interface also includes a second component including a rotational securement catch. The second component also includes a second stop arrangement including a fourth stop surface that faces in the second axial direction, a fifth stop surface that faces in the first axial direction, and a sixth stop surface that faces in a second rotational direction about the axis that is opposite from the first rotational direction. The turn-to-secure connection interface is positionable in a first rotational state in which the first stop surface opposes the fourth stop surface, the second stop surface is rotationally offset from the fifth stop surface, and the third stop surface is rotationally offset from the sixth stop surface by a rotation angle less than or equal to 360 degrees. The turn-to-secure connection interface is also positionable in a second rotational state in which the first stop surface opposes the fourth stop surface, the second stop surface opposes the fifth stop surface, and the third stop surface opposes and is adjacent to the sixth stop surface. The turn-to-secure connection interface is movable from the first rotational state to the second rotational state by rotating the first and second components relative to one another through the rotation angle. The rotational securement latch and the rotational securement catch circumferentially oppose one another when the turn-to-secure connection interface is in the second rotational state to resist the turn-to-secure interface from rotating from the second rotational state to the first rotational state. Contact between the rotational securement latch and the rotational securement catch as the turn-to-secure connection interface is moved from the first rotational state to the second rotational state causes the rotational securement latch to resiliently flex from a securement position to a clearance position to allow the rotational securement latch and the rotational securement catch to move rotationally past one another. The rotational securement latch elastically returns to the securement position after the rotational securement latch and the rotational securement catch have moved past one another to resist the turn-to-secure interface from rotating from the second rotational state to the first rotational state. 
     Another aspect of the present disclosure relates to a turn-to-secure connection interface including a first component defining a first axis and a second component defining a second axis. The first and second components are configured to be axially inserted together and mechanically coupled together when the first and second components are co-axially aligned. The first component includes a first stop arrangement and the second component includes a second stop arrangement. The first and second components are configured to be rotated relative to one another about the first and second axes between first and second rotational states when the first and second components have been axially inserted together. The first and second stop arrangements are configured to limit a range of rotational movement between the first and second rotational states. The first and second stop arrangements are also configured to allow the first and second components to be axially separated from one another when the first and second components are in the first rotational state, and to prevent the first and second components from being axially separated from one another when the first and second components are in the second rotational state. The first and second components further include a snap-fit arrangement for resisting movement of the first and second components from the second rotational state to the first rotational state. 
     Another aspect of the present disclosure relates to a fiber optic assembly including a fiber optic connector having a connector end. The fiber optic connector defines an axis. The fiber optic connector supports an optical fiber having a fiber end adjacent the connector end. The fiber optic connector further includes a retention sleeve. The fiber optic assembly also includes a cap that mounts over the connector end for protecting the fiber end. The cap is secured to the fiber optic connector by the retention sleeve. The retention sleeve and the cap are axially insertable together and when inserted together are rotatable relative to one another between a first rotational state and a second rotational state. The cap is axially removable from the fiber optic connector when the retention sleeve and the cap are in the first rotational state. The cap is not axially removable from the fiber optic connector when the retention sleeve and the cap are in the second rotational state. The cap and the retention sleeve include a snap-fit interface for retaining the cap and the retention sleeve in the second rotational state. The snap-fit interface is required to be damaged to move the retention sleeve and the cap from the second rotational state to the first rotational state. 
     A further aspect of the present disclosure relates to a fiber optic connector including a connector body defining a connector axis. The fiber optic connector also includes a retention sleeve for securing the fiber optic connector to a fiber optic adapter. The retention sleeve is mounted on the connector body and is turnable relative to the connector body about the connector axis. The retention sleeve includes a stop arrangement within the retention sleeve adapted to interface with a corresponding stop arrangement of the fiber optic adapter. The stop arrangement of the retention sleeve includes axial stop surfaces that face in opposite first and second axial directions along the connector axis. The stop arrangement of the retention sleeve also includes rotational stop surfaces that face in opposite first and second rotational directions about the connector axis. 
     Still another aspect of the present disclosure relates to a fiber optic adapter including an adapter body defining an adapter axis. The adapter body includes a stop arrangement integrated within an exterior of the adapter body for interfacing with a corresponding stop arrangement of a fiber optic connector. The stop arrangement of the adapter body includes axial stop surfaces that face in opposite first and second axial directions along the adapter axis. The stop arrangement of the adapter body also includes rotational stop surfaces that face in opposite first and second rotational directions about the adapter axis. 
     A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the examples disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows: 
         FIG. 1  depicts a fiber optic connector and a corresponding fiber optic adapter including a turn-to-secure connection interface in accordance with the principles of the present disclosure for mechanically securing the fiber optic connector and the fiber optic adapter together; 
         FIG. 2  is another view of the fiber optic adapter and the fiber optic connector of  FIG. 1 ; 
         FIG. 3  is a further view of the fiber optic connector and the fiber optic adapter of  FIG. 1 ; 
         FIG. 4  is a perspective view showing a first end of a retention sleeve of the fiber optic connector of  FIGS. 1-3  which forms part of the turn-to-secure connection interface; 
         FIG. 5  is another perspective view of the first end of the retention sleeve of  FIG. 4 ; 
         FIG. 6  is a perspective view of an opposite second end of the retention sleeve of  FIG. 4 ; 
         FIG. 7  is an end view of the first end of the retention sleeve of  FIG. 4 ; 
         FIG. 8  is a side view of the retention sleeve of  FIG. 4 ; 
         FIG. 9  is a diagrammatic view in which the retention sleeve of  FIG. 4  has been axially cut and laid flat so that an interior of the retention sleeve is visible in plan view, a circumference of the retention sleeve is labeled C and a length of the retention sleeve is labeled L; 
         FIG. 10  is a perspective view of the fiber optic adapter of  FIGS. 1-3  showing an example snap-fit latch; 
         FIG. 11  is a side view of the fiber optic adapter of  FIG. 10 ; 
         FIG. 12  is another side view of the fiber optic adapter of  FIG. 10 ; 
         FIG. 13  is an end view of the fiber optic adapter of  FIG. 10 ; 
         FIG. 14  is a diagrammatic view of a portion of the fiber optic adapter of  FIGS. 10-13  in which the portion has been cut axially and laid flat such that an exterior of the entire adapter body is visible in plan view, a circumference of the adapter body is labeled C and a length of the portion of the adapter body is labeled L; 
         FIG. 15  is a diagrammatic, laid flat view showing the turn-to-secure interface of the fiber optic connector and fiber optic adapter of  FIGS. 1-3  prior to the interface being axially inserted together; 
         FIG. 16  shows the turn-to-secure interface of  FIG. 15  with the retention sleeve of the fiber optic connector and the adapter body of the fiber optic adapter inserted together in a first rotational state; 
         FIG. 17  shows the turn-to-secure connection interface of  FIGS. 15 and 16  turned to a second rotational state; 
         FIG. 18  is a perspective view depicting the fiber optic connector of  FIGS. 1-3  shown aligned with a corresponding dust cap; 
         FIG. 19  is a perspective view of the dust cap of  FIG. 18 ; 
         FIG. 20  is an end view of the dust cap of  FIG. 19 ; 
         FIG. 21  is an end view of the fiber optic connector of  FIGS. 1-3 and 18 ; 
         FIG. 22  depicts another snap-fit latch in accordance with the principles of the present disclosure; 
         FIG. 23  depicts still another snap-fit latch in accordance with the principles of the present disclosure; 
         FIG. 24  depicts a cantilever type snap-fit latch in accordance with the principle of the present disclosure; 
         FIG. 25  depicted another cantilever type snap-fit latch in accordance with the principles of the present disclosure; 
         FIG. 26  is another view of the latch of  FIG. 25 ; 
         FIG. 27  is a further view of the latch of  FIG. 25 ; 
         FIG. 28  depicts an example tapered lead-in for an interlock in accordance with the principles of the present disclosure; 
         FIG. 29  depicts another example of a tapered lead-in for an interlock in accordance with the principles of the present disclosure; 
         FIG. 30  depicts a fiber optic adapter including a coupling arrangement in accordance with the principles of the present disclosure that forms part of a turn-to-secure connection interface; 
         FIG. 31  is a cross-sectional view of the fiber optic adapter of  FIG. 30 ; 
         FIG. 32  is another cross-sectional view of the fiber optic adapter of  FIG. 30 ; 
         FIG. 33  is an exploded view of a fiber optic connector in accordance with the principles of the present disclosure; 
         FIG. 34  is an assembled view of the fiber optic connector of  FIG. 33 ; 
         FIG. 35  shows the fiber optic connector of  FIG. 34  with an outer fastener and outer dust cap removed; 
         FIG. 36  depicts a core assembly of the fiber optic connector of  FIG. 34 ; 
         FIG. 37  is a side view of the fiber optic connector of  FIG. 34  with the outer dust cap and outer fastener removed; 
         FIG. 38  is a perspective view of a portion of the assembly of  FIG. 37 ; 
         FIG. 39  is a cross-sectional view showing a portion of the assembly of  FIG. 37 ; 
         FIG. 40  is another cross-sectional view of the assembly of  FIG. 37 ; 
         FIG. 41  is an end view showing a rear latch arrangement integrated with a shroud of the assembly of  FIG. 37 ; 
         FIG. 42  is a perspective view of the outer fastener of the fiber optic connector of  FIG. 34 ; 
         FIG. 43  is a perspective view of the outer dust cap of the fiber optic connector of  FIG. 34 ; 
         FIG. 44  is a perspective view showing the outer dust cap of  FIG. 43  being used to pry open the outer fastener of  FIG. 42 ; and 
         FIG. 45  depicts a pre-assembly including the dust cap, lanyard, fastener and shroud of  FIG. 33 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1-3  depict a fiber optic connector  20  and a corresponding fiber optic adapter  22  including a turn-to-secure mechanical connection interface in accordance with the principles of the present disclosure for securing the fiber optic connector  20  and the fiber optic adapter  22  together. In the depicted example, the turn-to-secure connection interface includes a first component depicted as an outer adapter body  24  of the fiber optic adapter  22  and a second component depicted as an outer retaining sleeve  26  of the fiber optic connector  20 . The retaining sleeve  26  is mounted over a connector body  28  of the fiber optic connector  20  and configured to rotate relative to the connector body  28  about a central axis defined by the fiber optic connector  20 . It will be appreciated that the turn-to-secure connection interface incorporated as part of the retaining sleeve  26  and the outer adapter body  24  is adapted to retain the connector body  28  within the fiber optic adapter  22 . In use, the connector body  28  is inserted into the fiber optic adapter  22 , and then the retaining sleeve  26  is slid axially over the outer adapter body  24  to a first inserted position in which the retaining sleeve  26  and the outer adapter body  24  are at a first rotational state relative to one another. Next, the retaining sleeve  26  is turned relative to the connector body  28  and the outer adapter body  24  from the first rotational state to a second rotational state. In the first rotational state, the retaining sleeve  26  can be pulled axially from the outer adapter body  24 . In contrast, in the second rotational state, stop arrangements of the turn-to-secure connection interface prevent the retaining sleeve  26  from being axially pulled from the outer adapter body  24 . An internal stop, such as a shoulder within the retaining sleeve  26 , opposes a corresponding stop on the connector body  28  such that when the retaining sleeve  26  is in the second rotational state, the retaining sleeve  26  prevents the connector body  28  from being withdrawn from the fiber optic adapter  22 . In a preferred example, a snap-fit arrangement is provided for retaining the retaining sleeve  26  in the second rotational state relative to the outer adapter body  24 . 
     The outer adapter body  24  defines an adapter axis  30  (see  FIG. 13 ) and the retaining sleeve  26  defines a sleeve axis  32  (see  FIG. 7 ). The outer adapter body  24  and the retaining sleeve  26  are configured to be axially inserted together and mechanically coupled together when the outer adapter body  24  and the retaining sleeve  26  are co-axially aligned. The outer adapter body  24  includes a first stop arrangement  34  of the turn-to-secure connection interface and the retaining sleeve  26  defines a second stop arrangement  36  of the turn-to-secure connection interface. 
     Referring to  FIGS. 10-14 , the first stop arrangement  34  includes a plurality of triangular projections  38  at an exterior of the outer adapter body  24 . The triangular projections  38  are spaced about a circumference C of the outer adapter body  24 .  FIG. 14  shows the outer adapter body  24  axially cut at one circumferential location and laid flat so that the entire circumference C of the outer adapter body  24  and a length L of the outer adapter body  24  are shown in plan view. The triangular projections  38  are spaced uniformly about the circumference C. The first stop arrangement  34  also includes at least one snap-fit feature that forms part of the snap-fit arrangement. As depicted at  FIGS. 10-14 , the snap-fit feature includes two resilient rotational securement latches  40  positioned on opposite sides of the outer adapter body  24 . 
     The second stop arrangement  36  of the turn-to-secure connection interface includes a plurality of recesses  42  positioned within the interior of the retaining sleeve  26  (see  FIGS. 4-10 ). The recesses  42  are spaced uniformly about a circumference C of the retaining sleeve  26 . As shown at  FIG. 9 , the retaining sleeve  26  has been axially cut at one location and laid flat so that the entire interior of the retaining sleeve  26  is visible in plan view. As shown at  FIG. 9 , the recesses  42  are uniformly spaced along a circumference C of the retaining sleeve  26 . 
     The second stop arrangement  36  also includes a plurality of snap-fit features that are part of the snap-fit arrangement for retaining the retaining sleeve  26  in the second rotational state relative to the outer adapter body  24 . The snap-fit features are depicted as rotational securement catches  44  spaced uniformly about the circumference of the retaining sleeve  26  within the interior of retaining sleeve  26 . Each of the rotational securement catches  44  includes a ramp surface  46  and a securement surface  48 . 
     It will be appreciated that the first and second stop arrangements  34 ,  36  are adapted to provide the turn-to-secure connection interface with a number of functions. For example, when the retaining sleeve  26  and the outer adapter body  24  have been initially inserted together, the adapter axis  30  and the sleeve axis  32  are coaxially aligned and the retaining sleeve  26  can be rotated relative to the outer adapter body  24  about the axes  30 ,  32  between the first and second rotational states. The first and second stop arrangements  34 ,  36  are configured to limit a range of rotational movement that is permitted between the first and second rotational states. In one example, the range of rotational movement permitted is less than or equal to 360 degrees, or less than or equal to 180 degrees, or less than or equal to 90 degrees. In the depicted example, the interaction between the first and second stop arrangements  34 ,  36  limits the range of rotation between the first and second rotational states to less than or equal to 90 degrees. The first and second stop arrangements  34 ,  36  are also configured to allow the fiber optic adapter  22  and the retaining sleeve  26  to be axially inserted together and axially separated from one another when the retaining sleeve  26  and the outer adapter body  24  are in the first rotational state. Furthermore, the first and second stop arrangements  34 ,  36  are configured such that when the retaining sleeve  26  and the outer adapter body  24  are in the second rotational state, interference between the first and second stop arrangements  34 ,  36  prevents the retaining sleeve  26  from being axially removed from the outer adapter body  24 . 
     The snap-fit arrangement of the turn-to-secure connection interface is configured to resist rotational movement between the retaining sleeve  26  and the outer adapter body  24  toward the first rotational state when the outer adapter body  24  and the retaining sleeve  26  are in the second rotational state. The rotational securement latches  40  and the rotational securement catches  44  are configured such that contact between the ramp surfaces  46  of the rotational securement catches  44  and the rotational securement latches  40  as the retaining sleeve  26  is rotated from the first rotational state to the second rotational state causes the rotational securement latches  40  to resiliently flex from a securement position to a clearance position to allow the rotational securement latches  40  and the rotational securement catches  44  to move rotationally past one another. The rotational securement latches  40  are configured to elastically return to the securement position after the rotational securement latches  40  and the rotational securement catches  44  have moved past one another. Once the retaining sleeve  26  has been moved to the second rotational state and the rotational securement latches  40  have moved back to the securement position the securement surfaces  48  of the rotational securement catches  44  oppose stop surfaces  50  at sides of the rotational securement latches  40  to resist the retaining sleeve  26  from rotating from the second rotational state back to the first rotational state. 
     Referring to  FIGS. 10 and 14 , the rotational securement latches  40  on the outer adapter body  24  each are formed by a flexible beam  62  having first and second opposite ends  64 ,  66  that are integrally formed and fixed with respect to the main body of the outer adapter body  24 . An open space or region  68  is defined between each of the flexible beams  62  and the main body of the outer adapter body  24  for providing space that allows the flexible beams  62  to flex radially inwardly relative to the adapter axis  30  when contacted by corresponding ramp surfaces  46  of one of the rotational securement catches  44 . The flexible beams  62  each include a rotational stop surface  70  that faces in a first rotational direction  72  and a ramp engagement surface  74  that faces in a second rotational direction  76  opposite from the first rotational direction  72 . When the retaining sleeve  26  and the outer adapter body  24  are rotated relative to one another between the first rotational state and the second rotational state, the ramp surfaces  46  of the rotational securement catches  44  engage the ramp engagement surfaces  74  of the flexible beams  62  thereby causing the flexible beams  62  to flex radially inwardly to permit the rotational securement catches  44  to move past the flexible beams  62 . Once the rotational securement catches  44  move past the flexible beams  62 , the flexible beams  62  resiliently return to their non-deflected state such that the rotational stop surfaces  70  oppose the rotational stop surfaces  48  of the corresponding securement catches  48 . The rotational stop surfaces  48  of the securement catches  44  face in the second rotational direction  76 . 
     In certain examples, engagement between the rotational stop surfaces  70  and the rotational stop surfaces  48  resist the retaining sleeve  26  from being rotated relative to the outer adapter body  24  from the second rotational state back to the first rotational state. In certain examples, engagement of the stop surfaces  70 ,  48  is sufficiently robust that the flexible beams  62  are required to be damaged or broken in order for the retaining sleeve  26  to be moved from the second rotational position back to the first rotational position. Thus, in such situations, to move the retaining sleeve  26  from the second rotational position back to the first rotational position, sufficient torque must be applied to the retaining sleeve  26  to cause the flexible beams  62  to break. In certain examples, the flexible beams  62  can be designed to control the amount of force required to break the flexible beams  62 . For example, by altering the thickness of the flexible beams  62  or by providing regions in the flexible beams having reduced strength (e.g., notched regions, partially cut regions, etc.), the force required to break the flexible beams  62  can be customized for different applications (e.g., see  FIGS. 22 and 23 ). In certain examples, damage to the flexible beams  62  can be used as a visible indicator that the retaining sleeve  26  has been moved from the second rotational position back to the first rotational position. The flexible beams  62  can thus function as tampering indicators. 
     Referring still to  FIGS. 10 and 14 , the first stop arrangement  34  includes axial stop surfaces  54  that face in a first axial direction  58  along the adapter axis  30 , and stop surfaces  55  that face in a second axial direction  60  along the adapter axis  30 . The first and second axial directions  58 ,  60  are opposite from one another. The first stop arrangement  34  also includes rotational stop surfaces  57  that face in the second rotational direction  76 . The axial stop surfaces  54  are defined by corners of the first triangular projections  38 , the axial stop surfaces  55  are defined by sides of the first triangular projections  38  that are opposite from the corners defining the stop surfaces  54 , and the rotational stop surfaces  57  are defined by sides of the first triangular projections  38  that extend between the axial stop surfaces  54 ,  55 . It will be appreciated that the first stop arrangement  34  is defined in part by the first triangular projections  38  and in part by the rotational securement latches  40 . 
     It will be appreciated that the second stop arrangement  36  is defined in part by the recesses  42  and in part by the rotational securement catches  44  within the interior of the retaining sleeve  26 . For example, referring to  FIG. 9 , the rotational securement catches  44  define the rotational stop surfaces  48  that face in the second rotational direction  76 . Also, the triangular recesses  42  include axial stop surfaces  56  that face in the second axial direction  60 , axial stop surfaces  59  that face in the first axial direction  58  and rotational stop surfaces  61  that face in the first rotational direction  72 . The recesses  42  include triangular portions  63  shaped to compliment the shape of the triangular projections  38 . Access gaps  52  are tapered to facilitate guiding the triangular projections  38  into the recesses  42  as the retaining sleeve  26  and the outer adapter body  24  are axially inserted together. 
     As used herein, a surface “faces in a direction” if the surface faces at least partially in the direction. 
       FIG. 15  shows the retaining sleeve  26  axially aligned with the outer adapter body  24  prior to axial insertion between the outer adapter body  24  and the retaining sleeve  26 . As so positioned, the triangular projections  38  on the outer adapter body  24  align with the gaps  52  that provide access to the recesses  42  within the interior of the retaining sleeve  26 . When the retaining sleeve  26  and the outer adapter body  24  are axially inserted together, the taper of the triangular projections  38  as well as the tapered configuration of the access gaps  52  facilitates guiding the triangular projections  38  into the recesses  42 . 
       FIG. 16  shows the retaining sleeve  26  and the outer adapter body  24  axially inserted together, with the outer adapter body  24  and the retaining sleeve  26  in the first rotational state. In the first rotational state, the stop surfaces  54  of the outer adapter body  24  oppose or engage the corresponding stop surfaces  56  of the retaining sleeve  26  to limit the depth of axial insertion that can take place between the retaining sleeve  26  and the outer adapter body  24 . Also, the axial stop surfaces  55  of the first stop arrangement  34  are rotationally offset from the axial stop surfaces  59  of the second stop arrangement  36  such that no interference is provided between the stop surfaces  55 ,  59  that would prevent the outer adapter body  24  and the retaining sleeve  26  from being axially separated from one another. Thus, in the first rotational state of  FIG. 16 , the outer adapter body  24  and the retaining sleeve  26  can be axially separated from one another. Additionally, the rotational stop surfaces  57  of the first stop arrangement  34  are rotationally offset from the rotational stop surfaces  61  of the second stop arrangement  36  by a rotation angle A. In certain examples, the rotational angle A is no more than about 90 degrees. In one example, the rotation angle A is about 90 degrees which corresponds generally to a quarter turn of the retaining sleeve  26  relative to the outer adapter body  24 . In one example, the rotation angle A is about 45 degrees. 
       FIG. 17  shows the outer adapter body  24  and the retaining sleeve  26  in the second rotational state. To move the outer adapter body  24  and the retaining sleeve  26  from the first rotational state to the second rotational state, the retaining sleeve  26  can be rotated in the first direction  72  relative to the outer adapter body  24  through the angle A. When the retaining sleeve  26  is rotated from the first rotational state to the second rotational state, the triangular projections  38  are received within the triangular portions  63  of the recesses  42  of the retaining sleeve  26  as shown at  FIG. 17 . As so positioned, the stop surfaces  54  of the first stop arrangement  34  continue to oppose the stop surfaces  56  of the second stop arrangement  38 . Also, the stop surfaces  55  of the first stop arrangement  34  oppose the stop surfaces  59  of the second stop arrangement  36  such that interference between the stop surfaces  55 ,  59  prevents the retaining sleeve  26  and the outer adapter body  24  from being axially separated from one another. Further, the rotational stop surfaces  57  of the first stop arrangement  34  oppose and are adjacent to the rotational stop surfaces  61  of the second stop arrangement  36  to limit the range of rotational movement that is possible between the retaining sleeve  26  and the outer adapter body  24  as the retaining sleeve  26  is rotated between the first and second rotational states. 
     When the retaining sleeve  26  is in the second rotational state, the rotational stop surfaces  48  of the rotational securement catches  44  oppose the rotational stop surfaces  70  of the rotational securement latches  40 . In this way, the stop surfaces  70 ,  48  resist rotation of the retaining sleeve  26  from the second rotational position back to the first rotational position. As the retaining sleeve  26  is rotated from the first rotational position to the second rotational position, the ramp engagement surfaces  74  of the rotational securement latches  40  are engaged by the ramp surfaces  46  of the rotational securement catches  44  causing the rotational securement latches  40  to resiliently flex from a securement position to a clearance position to allow the rotational securement catches  44  to move rotationally past the rotational securement latches  40 . The rotational securement latches  40  elastically return to their securement positions after the rotational securement catches have moved past the rotational securement latches  40 . Once the rotational securement latches  40  move back to the securement positions, the rotational stop surfaces  70  of the rotational securement latches  40  oppose the rotational stop surfaces  48  of the rotational securement catches  44  to resist rotation of the retaining sleeve  26  from the second rotational state back to the first rotational state. 
     In the depicted example, the rotational stop surfaces  48  of the rotational securement catches  44  and the rotational stop surfaces  70  of the rotational securement latches  40  are arranged generally perpendicular to the direction of rotation  76  required to move the retaining sleeve  26  from the second rotational position back to the first rotational position. Thus, it generally would be required to break the rotational securement latches  40  in order to move the retaining sleeve  26  from the second rotational state back to the first rotational state. In other examples, the rotational stop surfaces  48  and/or the rotational stop surfaces  70  may be angled relative to the direction of rotation  76  such that the surfaces resist moving the retaining sleeve  26  from the first rotational state to the second rotational state, but will cause the rotational securement latches  40  to flex radially inwardly to allow the retaining sleeve  26  to be moved from the first rotational state to the second rotational state if sufficient torque is applied to the retaining sleeve  26 . It will be appreciated that the amount of torque required is dependent upon the selected angles of the stop surfaces. In this type of configuration, the retaining sleeve  26  can be moved from the first rotational state to the second rotational state without breaking the rotational securement latches  40 . 
       FIG. 18  shows the fiber optic connector  20  aligned with a corresponding dust cap  100 . The fiber optic connector has a connector end  102 . The fiber optic connector defines an axis  104 . The fiber optic connector  20  supports an optical fiber  106  which has a fiber end adjacent the connector end  102 . In the depicted example, the optical fiber  106  is supported within a ferrule  107 . In other examples, ferrule-less connectors may be used. The retaining sleeve  26  is rotatably mounted on the connector body  28 . The dust cap  100  includes the first stop arrangement  36 . The cap  100  mounts over the connector end  102  for protecting the end of the optical fiber  106 . The cap  100  is secured to the fiber optic connector  20  by the retaining sleeve  26 . The retaining sleeve  26  and the cap  100  are axially insertable together and when inserted together are rotatable relative to one another between a first rotational state and a second rotational state in the same manner described with respect to the relationship between the retaining sleeve  26  and the outer adapter body  24 . The cap  100  is axially removable from the connector  20  when the retaining sleeve  26  and the cap  100  are in the first rotational state. The cap  100  is not axially removable from the fiber optic connector  20  when the retaining sleeve  26  and the cap  100  are in the second rotational state due to interference between the first and second stop arrangements  34 ,  36 . 
     The snap-fit arrangement provided as part of the first and second stop arrangements  34 ,  36  is configured for retaining the cap  100  and the retaining sleeve  26  in the second rotational state. In certain examples, the snap-fit arrangement is required to be damaged to move the retaining sleeve  26  and the cap  100  from the second rotational state back to the first rotational state. In this way, the snap-fit interface can function as a tampering indicator. For example, once the fiber optic connector  20  has been processed and cleaned in the factory, the cap  100  can be factory installed on the fiber optic connector  20  by interlocking the dust cap  100  with the retaining sleeve  26 . Preferably, the dust cap  100  is not removed prior to the fiber optic connector being used in the field. Therefore, when the fiber optic connector is ready to be used in the field, the field technician will rotate the outer adapter body  24  and the retaining sleeve  26  from the second rotational position back to the first rotational position thereby breaking the snap-fit arrangement. If the snap-fit arrangement has already been broken, the field technician will have notice that the fiber optic connector may have been compromised. 
     As used herein, the first rotational state can be referred to as a non-coupled rotational state and the second rotational state can be referred to as a coupled rotational state. In the non-coupled rotational state, the first and second stop arrangements  34 ,  36  do not interlock such that the two connectable parts (e.g. the adapter body  24  and the retaining sleeve  26 ) can be axially separated from one another. In contrast, in the coupled rotational state, the stops of the two components that are being coupled together to overlap one another and to prevent the two components from being disengaged in an axial direction. Further, in the coupled rotational position, snap-fit structures of the components are preferably also interlocked to inhibit the components from being rotated from the coupled rotational state back to the non-coupled rotational state. In certain examples, the snap-fit arrangement can include a detent that can be overcome when sufficient torque is applied between the components to disengage the snap-fit connection. In certain examples, the detent configuration is reusable and is designed not to break when the components are moved from the coupled rotational position back to the non-coupled rotational position. In other examples, the snap-fit configuration can be adapted as a single-use connection, and is required to be broken to move the coupled components from the coupled rotational position back to the non-coupled rotational position. In other examples, the snap-fit configuration can include a latch capable of being manually moved (e.g., depressed) from a retaining position to a release position to allow the coupled components to be moved from the coupled rotational position back to the non-coupled rotational position. In such an example, the latch may include a portion that is positioned outside the coupled components (e.g., outside the retaining sleeve  26 ) that can be accessed to move the latch to the release position in which the latch does not obstruct rotational movement of the components from the coupled rotational position back to the non-coupled rotational position. 
     In certain examples, once the two components are fully axially inserted together, the components can be rotated from the non-coupled rotational state to the coupled rotational state without utilizing or requiring axial movement between the components. Thus, in certain examples, the snap-fit configuration for retaining the components in the coupled rotational state can be engaged without requiring axial movement between the two components being coupled together. For example, unlike a standard bayonet connection, one of the components does not need to backtrack in a withdrawal direction (e.g., a direction opposite from the insertion direction) to retain the components in the coupled rotational position. Further, in certain examples, the turn-to-secure interface as disclosed herein does not require a separate coil spring or other separate spring mechanism for applying axial spring load on either of the components being coupled together. In certain examples, the snap-fit connection for retaining the first and second components in the coupled rotational state can be engaged by pure rotational movement between the two components. Thus, in certain examples, an axial component movement is not required to engage the snap-fit connection between the components. 
       FIG. 22  depicts an alternative rotational securement latch  40   a  in accordance with the principles of the present disclosure. The rotational securement latch  40   a  includes a beam  300  having opposite fixed ends. An open space is located beneath the beam  300 . Notches  301  are provided at opposite sides of the beam adjacent the ends of the beam  300 . The beam  300  has a length that extends in a direction transverse with respect to the rotational directional of movement of the first and second components being coupled together. Thus, the beam  300  is transverse with respect to the circumferential direction. 
       FIG. 23  shows another rotational securement latch  40   b  in accordance with the principles of the present disclosure. The rotational securement latch  40   b  also includes a beam  310  having fixed opposite ends. An attachment point  311  of one of the ends of the beam  310  has a reduced cross-sectional area as compared to the opposite end  313 . Open space is located between the beam  310  and the main body of the component to which the beam is coupled. The beam  310  has a length that is transverse with respect to an orientation of rotation of the components being coupled together. 
       FIG. 24  depicts another rotational securement latch  40   c  in accordance with the principles of the present disclosure. The rotational securement latch  40   c  has cantilevered configuration including one end  315  integral with its corresponding component and an opposite free end  317 . A portion  318  of the beam can be contoured to facilitate sliding a rotational securement catch over the beam. It will be appreciated that any of the beams  40   a - 40   c  can be used in combination with the rotational securement catches  44  previously described which are part of the second stop arrangement provided within the retaining sleeve  26 . Further, all of the beams depicted in  FIGS. 22-24  have major dimensions that extend transversely relative to the direction of rotation in which relative rotational movement is generated between the first and second components desired to be coupled together. 
       FIGS. 25-27  depict a further rotational securement latch  40   d  in accordance with the principles of the present disclosure. The rotational securement latch  40   d  can be substituted for the rotational securement latch  40  and can be incorporated as part of the first stop arrangement  34 . The rotational securement latch  40   d  can be configured to provide a snap-fit connection with the rotational securement catches  44  of the second stop arrangement  36 . Unlike the previous rotational securement latches, the rotational securement latch  40   d  has beam  340  with a cantilevered configuration and a length that extends in a direction d parallel to the direction of rotation in which the first and second components desired to be coupled together are rotated when the components are rotated between the non-coupled rotational position and the coupled rotational position. The beam  340  has a fixed end  341  and a free end  342 . The free end  342  is circumferentially offset from the fixed end  341 . A contoured ramp feature  344  is defined at a location axially offset from the primary length of the beam. The ramp feature  344  is configured for facilitating passing the rotational securement catches  44  over the rotational securement latch  40   d  as the components are move from the non-coupled rotational position toward the coupled rotational position. When the rotational securement catches  44  engage the contoured ramp surface, the cantilevered beams flex radially inwardly to allow the rotational securement catches  44  to pass by the latches  40   d . Once the rotational securement catches  44  pass by the latches  40   d  and the components reach the coupled rotational state, the beams  340  elastically turn to the non-deflected state and free ends of the beams oppose the rotation securement catches  44  to prevent rotation of the components from the coupled rotational state back to the non-coupled rotational state. 
     It will be appreciated that the latches  40   a - 40   d  can readily be used prevent rotation of a component such as the retaining sleeve  26  from the coupled rotational state back to the non-coupled rotational state. The latch  40   d  is configured such that when latched with the retaining sleeve  26 , a portion of the latch  40   d  is accessible from outside the retaining sleeve  26  to allow the latch to be manually flexed and released with respect to the retaining sleeve to allow the retaining sleeve to be rotated from the coupled rotational state back to a non-coupled rotational state. The latch  40   d  and other latches discloses herein can be integrated with structures such as fiber optic adapter housings, fiber optic connector housings, dust caps, connector shrouds, and the like. 
       FIGS. 28 and 29  show modified configurations for the second stop arrangement  36  where in each figure a modified version of stop  38  is shown moving from the non-coupled rotational state to the coupled rotational state. At  FIG. 28 , stop  38  has been modified with a taper or chamfer  38   a  to facilitate rotating the first and second components relative to one another. At  FIG. 29 , stop  38  has been modified with chamfer  38   a  and recess  42  has been modified with a taper or chamfer to facilitate rotating the first and second components relative to one another. For example, axial stop surface  59  can include angled or a chamfered lead-in portion  59   a  that is angled slightly relative a primary stop surface  59   b . The chamfered nature of the surfaces  30   a ,  59   a  facilitates rotating the first and second components desired to be coupled together from the non-coupled rotational state to the coupled rotational state. Specifically, the two components can be rotated from the non-coupled rotational state to the coupled rotational state even if initially the two parts are not fully inserted axially to one another. In the case where the two components are not fully axially inserted together at the time rotation from the non-coupled rotational state toward the coupled rotational state is initiated, the tapered lead in surfaces  59   a ,  38   a  engage one another and force two components to the fully inserted position as rotation occurs between the first and second components. Once the first and second components are in the coupled rotational position, substantially full contact is maintained between the stop surfaces  59  and the stop surfaces  55 . For example, stop surface  55  can include angled stop surface  38   b  that opposes surface  59   a  and stop surface  55  can include angled surface  59   b  that opposes surface  38   a.    
       FIGS. 30-32  depict another fiber optic adapter  400  in accordance with the principles of the present disclosure. The fiber optic adapter  400  includes a first stop arrangement  34   a  that is a modified version of the first stop arrangement  34  and that is compatible with the second stop arrangement  36 . Similar to the first stop arrangement  34 , the first stop arrangement  34   a  includes the plurality of triangular projections  38  adapted to interlock with the recesses  42  of the second stop arrangement  36  when the first and second stop arrangements are rotated relative to one another to the coupled rotational state. The first stop arrangement  34   a  also includes at least one snap-fit feature adapted to provide a snap-fit connection with the rotational securement catches  44  of the second stop arrangement  36  when the second stop arrangements  34   a  and  36  are coupled together. The snap-fit feature is depicted as including a detent  40   e  (e.g., a bump) adapted to engage with the corresponding one of the catches  44  when the first and second stop arrangements  34   a ,  36  are coupled together. In certain examples, the body (e.g., the retaining sleeve  26 ) carrying the second stop arrangement  36  is sufficiently flexible to enable the ramp  46  to ride over the detent  40   e  and the stop  48  to snap over the detent  40   e . The detent  40   e  is configured to retain the components desired to be coupled together in the coupled rotational state, but allows for rotation from the coupled rotational state to the non-coupled rotational state if sufficient torque is applied between the components. Preferably, detent  40   e  does not break when the components are rotated from the coupled rotational state back to the non-coupled rotational state. Thus, the first stop arrangement  34   a  is adapted to be used multiple times as compared to being a single use arrangement. 
     Additionally, in certain implementations, the fiber optic adapter  400  includes a retention collar  450  that can be used to selectively inhibit rotation of the retaining sleeve  26  relative to the fiber optic adapter  400  from the coupled rotational state to the non-coupled rotational state. The retention collar  450  can be used to provide rotational locking of the retaining sleeve  26  with or without the detent feature  40   e  or other type of snap-fit feature that inhibits rotation when engaged. The retention collar  450  can be slid between a retracted position and an extended position. As will be described in more detail herein, when in the extended position, the retention collar  450  inhibits rotation of the retaining sleeve  26  relative to the adapter  400 . When in the retracted position, the retention collar  450  allows rotation of the retaining sleeve  26  relative to the adapter  400 . 
     The retention collar  450  is mounted so as to not rotate relative to the main body of the fiber optic adapter  400 . For example, an internal portion of the retention collar  450  can interlock with a corresponding structure on the adapter  400  so as to prevent the retention collar  450  from rotating relative to the adapter  400  but to allow the retention collar  450  to be moved axially relative to the adapter  400  between the extended orientation and the retracted orientation. In one example, the interlock can include an axial rail that fits within an axial groove. 
     In certain examples, a detent arrangement  457  can be used to retain the retention collar  450  in the extended position and/or in the retracted position. In the depicted example of  FIG. 31 , the detent arrangement  457  includes a bump  459  disposed between first and second recesses (e.g., grooves)  456 ,  458  defined in the adapter  400 . An inward protrusion  453  carried by the retention collar  450  snaps into the first recess  456  when disposed in the retracted position and snaps into the second recess  458  when disposed in the extended position. The inward protrusion  453  rides over the bump  459  when sufficient force is applied to the retention collar  450 . Accordingly, the retention collar  450  is held in one position until the user chooses to move the retention collar  450  to the other position. 
     It will be appreciated that the retention collar can include internal retention members  455  (e.g., fingers) as shown in  FIG. 32 . The retention members  455  fit inside the retaining sleeve  26 . When the retention collar  450  is moved from the retracted position to the extended position while the retaining sleeve  26  is in the coupled rotational position, the retaining members  455  oppose the rotational securement catches  44  to prevent the retaining sleeve  26  from being rotated from the coupled rotational state to the uncoupled rotational state. By moving the retention collar  450  from the extended position back to the retracted position, the retention members  455  clear the securement catches  44 . Thereby the retaining sleeve  26  can be rotated from the coupled rotational state to the uncoupled rotational state. In certain examples, the retaining sleeve  26  is rotated when both the retention collar  450  is retracted and when sufficient torque is applied to the retaining sleeve  26  to overcome the detent  40   e  and move the retaining sleeve  26  from the coupled rotational state back to the non-coupled rotational state. 
     In certain examples, the retention collar  450  can be spring biased toward the extended position. In this way, the retention collar  450  can automatically move from the retracted position to the extended position once the retaining sleeve  26  is turned from the non-coupled rotational state to the coupled rotational state. To de-couple the retaining sleeve  26 , the collar  450  can be manually slid from the extended position the retracted position against the bias of the spring to allow for rotation of the sleeve  26  from the coupled rotational state to the non-coupled rotational state. Insertion of the core assembly into the adapter  400  can cause movement of the collar  450  from the extended position to the retracted position (e.g., via physical contact between the retaining sleeve and the core assembly) against the bias of the spring. 
       FIGS. 33 and 34  depict an example fiber optic connector  520  in accordance with the principles of the present disclosure. The fiber optic connector  520  includes a core assembly  522  terminated to a fiber optic cable  524 . The core assembly  522  is configured to be plugged directly into an optical adapter, such as any of the optical adapter  24 ,  400  disclosed herein. In certain examples, a retaining sleeve  542  carried by the core assembly  522  carries either the first stop arrangement  34  of the turn-to-secure connection interface or the second stop arrangement  36  of the turn-to-secure connection interface. The retaining sleeve  542  also may carry either part of a snap-fit arrangement (e.g., rotational securement latches  40  or the rotational securement catches  44 ). Accordingly, the stop arrangement  34 ,  36  of the retaining sleeve  542  may engage the stop arrangement  36 ,  34  of the adapter to secure the core assembly  522  to the adapter. 
     In certain implementations, the fiber optic connector  520  also is configured to receive a shroud  526  that mounts over a core  534  of the core assembly  522  and an outer fastener  528  that mounts over the shroud  526  to allow the core assembly  522  to be mounted within a different type of optical adapter, dust cap, or other mating component. The shroud carries the stop arrangement and snap-fit components that engage the corresponding stop arrangement and snap-fit components on the retaining sleeve  542  to secure the shroud to the core assembly  522 . The outer fastener  528  has a connection interface arrangement adapted for mating with a corresponding connection interface arrangement integrated with a structure such as a fiber optic adapter, a dust cap or another fiber optic connector to provide mechanical connection therein between. In the depicted example, the connection interface arrangement of the outer fastener  528  is depicted as including external threads, but alternative embodiments could include a bayonet arrangement, internal threads, a stop arrangement, or other type of rotational securement arrangement. In certain implementations, the core assembly  522  may receive any of a plurality of shrouds that each have a different form factor or keying arrangement for mating with different types of adapters. In certain implementations, each shroud  526  may be coupled to any of a plurality of outer fasteners  528  that each have a different connection interface for coupling to different types of adapters. 
     In certain examples, the fiber optic connector  520  includes an outer dust cap  530  that couples to the outer fastener  528  and a lanyard  532  for tethering the outer dust cap  530  to the core assembly  522 . In the depicted example, the outer fastener  528  includes external threads adapted to engage with internal threads of the dust cap  530  to secure the dust cap over the core of the core assembly  522 . When it is desired to optically connect the fiber optic connector  520  to another fiber optic connector, either directly or through an intermediate fiber optic adapter, the outer dust cap  530  is disengaged from the outer fastener  528  thereby allowing the outer fastener  528  to be used to secure the fiber optic connector  520  to a mating fiber optic connector or fiber optic adapter. 
     The core  534  of the core assembly  522  includes an end  536  supporting a ferrule  538  (see  FIG. 36 ). It will be appreciated that the ferrule  538  is adapted for supporting an end portion of an optical fiber  539  corresponding to the fiber optic cable  524 . As shown at  FIGS. 33 and 35 , the ferrule  538  is protected by a removable inner dust cap  540 . The core assembly  522  also includes a retaining sleeve  542  for securing the core assembly  522  to a rear end  544  of the shroud  526 . It will be appreciated that the shroud  526  fits over the core  534  and can include a key arrangement  546  adapted to mate with a corresponding arrangement provided in a fiber optic adapter to ensure the fiber optic connector  520  is inserted into the fiber optic adapter at a particular rotational position. In certain examples, different shrouds having different configurations can be interchangeably mounted over the core  534  to provide compatibility with different types of fiber optic adapters (e.g., see U.S. Pat. No. 9,733,436, which is hereby incorporated by reference in its entirety). 
     It will be appreciated that a turn-to-secure connection interface can also be provided between the rear end  544  of the shroud  526  and the retaining sleeve  542 . For example, rear end  544  of the shroud  526  can include a stop arrangement that interlocks with a corresponding stop arrangement of the retaining sleeve  542  when the retaining sleeve  542  and the rear end  544  of the shroud  526  are rotationally locked together (i.e., moved from a first rotational state in which the parts can be axially separated from one another to a second rotational state in which the parts are prevented from being axially separated from one another). The stop arrangements can be of the type previously described herein. 
     The interface can also include a snap-fit arrangement for retaining the retaining sleeve  542  in an interlocked rotational position (e.g., the second rotational state) relative to the rear end  544  of the shroud  526 . In the depicted example, the snap-fit arrangement includes resilient latches  548  provided on the shroud  526  (see  FIG. 41 ) that interlock with corresponding catches  550  (e.g., stops) of the retaining sleeve  542  (see  FIG. 36 ) when the retaining sleeve  542  is rotated relative to the shroud  526  to a retaining rotational position (e.g., the second rotational state). Engagement (e.g., latching) between the resilient latches  548  and the catches  550  prevents the retaining sleeve  542  from being rotated relative to the shroud  526  from the retaining rotational position back to the release rotational position (e.g., the first rotational state). It will be appreciated that when the retaining sleeve  542  is in the retaining rotational position relative to the shroud  526 , the retaining sleeve  542  and the shroud  526  are locked together. By contrast, when the retaining sleeve  542  is in the release rotational position relative to the shroud  526 , the retaining sleeve  542  and the shroud  526  can be axially separated from one another. 
     Referring to  FIGS. 35 and 37-41 , the resilient latches  548  of the snap-fit arrangement include release actuation portions  552  (e.g., tabs, buttons, bumps, etc.) that are exposed and accessible when the retaining sleeve  542  and the shroud  526  are mated together in the retaining rotational position (e.g., see  FIG. 39 ). The latches  548  include engagement portions  551  that project axially from the release actuation portions  552  (see  FIGS. 40 and 41 ). The engagement portions  551  move in unison with the release actuation portions  552 . The engagement portions  551  have stop surfaces  549  ( FIG. 41 ) that are adapted to engage the stops  550  of the retaining sleeve  542  (see  FIG. 36 ) to provide rotational locking. For example, the engagement with the ramped portion of the catches  550  deflects the engagement portions  551  (and hence the release actuation portions  552 ) inward to a non-latching position until the engagement portion  551  clears the stop  550 . Then the engagement portion  551  undeflects back to the latching position where the stop surface  549  abuts the shoulder of the stop  550 . The release actuation portions  552  of the latches  548  can be depressed to move the engagement portions  551  of the resilient latches  548  from a latching position to a non-latching position where the stop surface  549  clears the catch  550 . The resilient latches  548  are preferably spring-biased toward the latching position. When the resilient latches  548  have been depressed to the non-latching position, the snap-fit interface does not prevent the retaining sleeve  542  from being rotated relative to the shroud  526  from the retaining rotational position to the release rotational position. 
     When the outer fastener  528  is mounted over the shroud  526  as shown at  FIG. 34 , the outer fastener  528  covers and blocks access to the release actuation portions  552 . Therefore, while the outer fastener  528  is mounted over the shroud  526 , the release actuation portions  552  are inaccessible and the retaining sleeve  542  is prevented by the snap-fit interface from being rotated from its retaining rotational position to its release rotational position relative to the shroud  526 . To access the release actuation portions  552 , the outer fastener  528  can be removed from the shroud  526  by detaching the lanyard  532  from the outer fastener  528  and then breaking the outer fastener  528 . In certain examples, the outer fastener  528  can include a predefined break location  560  (see  FIG. 42 ). In one example, the pre-defined break location  560  can include a predefined break line  561  defined by a line of reduced cross-sectional area defined through a thickness of the fastener  528 . The reduced thickness can be provided by a longitudinal slit provided axially along the body of the outer fastener  528 . 
     In certain examples, a tool carried by the outer dust cap  530  can be used to break the outer fastener  528  along the predefined break line. In one example, a pry tool  570  can be integrated with the outer dust cap  530 . The pry tool  570  can be configured to fit within a pry tool receiving notch  572  defined by the outer fastener  528  at the predefined break location. By inserting the pry tool  570  in the pry tool receiving notch  572  and twisting the dust cap, the outer fastener  528  can be cracked along the longitudinal break line  561  or lines. In one example, break locations  560  are provided at opposite sides of the fastener  528  to allow the fastener  528  to be broken in half by breaking the fastener  528  at each of the break locations  560 . 
     It will be appreciated that during assembly of the fiber optic connector  520 , a rear end of the lanyard  532  and the outer fastener  528  are initially inserted over the core assembly  522 . Next, the shroud  526  is inserted over the core  534  of the core assembly  522  and the retaining sleeve  542  of the core assembly  522  is interlocked with the rear end  544  of the shroud  526  to mechanically couple the shroud  526  to the core assembly  524 . The outer fastener  528  is then slid forwardly over the shroud  526  past fastener latches  580  ( FIG. 37 ) that function to retain the outer fastener  528  on the shroud  526 . It will be appreciated that the outer fastener  528  can rotate about the shroud  526 . Thereafter, the front end of the lanyard  532  can be coupled to the outer dust cap  530  and the outer dust cap can be secured to the remainder of the fiber optic connector by threading the threaded interface of the outer fastener  528  into the threaded interface of the outer dust cap  530 . The fastener latches  580  prevent the outer fastener  528  from being removed from the shroud  526  without breaking the outer fastener  528  at the predefined break location. 
     Referring to  FIG. 45 , the dust cap  530 , lanyard  532 , fastener  528  and shroud  526  of  FIG. 33  can form an assembly  531  that is pre-assembled together prior to connection to the core assembly  522 . As depicted, one end of the lanyard  532  couples to the dust cap  530  (e.g., adjacent the front end of the dust cap) and the opposite end of the lanyard couples to the outer fastener  528  (e.g., adjacent a rear end of the fastener). A forward portion of the shroud  526  fits within the dust cap  530  and the fastener  528  mounts over a rear portion of the shroud  526 . The fastener  528  couples to the dust cap  530  by a turn-to-secure connection and retains the shroud  526  within the dust cap  530 . The pre-assembled nature of the assembly  531  prevents the loss of parts and facilitates use in the field. In certain examples, the core assembly  522  can be coupled to the shroud  526  via a turn-to-secure connection without requiring disassembly of the assembly  531 . For example, the core  534  of the core assembly  522  is inserted into the shroud  526  through a rear end the shroud  526  which is accessible at a rear end of the assembly  531 . Also, the retaining sleeve  542  of the core assembly  522  is interlocked with the rear end  544  of the shroud  526  to mechanically couple the shroud  526  to the core assembly  524 . It will be appreciated that a turn-to-secure connection interface at the rear end  544  of the shroud  526  is accessible at the rear end of the assembly  531  for coupling with the retaining sleeve  542 . In other examples, at least partial disassembly of the assembly  531  may be required for connection to the core assembly  522 . 
     It will be appreciated that the first and second stop arrangements disclosed herein provide two separate interlock functions when in the coupled rotational state. One of the interlock function provides interlocking features that interlock to resist axial movement between the two components desired to be coupled together. For example, the axial interlock features interlock to prevent a first one of the components from being axially disengaged or withdrawn from the second component. A second interlocking feature can be provided by a snap-fit feature that functions to prevent rotational movement between the two components when the two components are in the coupled rotational state. The second interlocking feature functions to prevent or resist the components from being rotated from the coupled rotational state in which the components are axially secured together to the non-coupled rotational state in which the two components can be axially separated from one another. The components can include fiber optic connectors, connector retention sleeves, fiber optic adapters, dust caps, retention sleeves, rotatable fastening elements, connector pieces, connector shrouds, and the like.