Optical waveguides – With disengagable mechanical connector – Optical fiber/optical fiber cable termination structure
Patent
1996-03-07
1997-03-11
Healy, Brian
Optical waveguides
With disengagable mechanical connector
Optical fiber/optical fiber cable termination structure
385 77, 385 78, 385 80, 385 81, 385 87, 385139, G02B 636
Patent
active
056110120
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention concerns a plug-type connector for one end of a fiber-optic cable, which cable contains at least one optical fiber surrounded by a fiber sheath, a strand-type strain-relief element, and a cable sheath. The connector includes a ferrule having a central longitudinal bore to receive an unsheathed optical fiber end, a ferrule-holder that receives the rear ferrule region and is mounted in a casing so that it can move axially against a restoring force, central openings in the ferrule-holder and in the casing, through which the optical fiber and the fiber sheath can move back into the cable sheath, and means for fastening the strain-relief element at its end to the casing.
BACKGROUND OF THE INVENTION
A known plug-type connector of this kind disclosed in EP-A1-0 330 399 comprises a coupling end-piece for connecting an optical cable to, for example, a further optical cable or to an optoelectronic component. The cable comprises at least one cable sheath, a strand-type strain-relief element (for example, KEVLAR.RTM. fibers), and an optical fiber that is surrounded by a protective fiber sheath (buffer).
The optical fiber end toward the coupling extends in a central longitudinal bore of a ferrule. The rear end of the ferrule is held by a ferrule-holder that has a stop surface for one end of a helical spring. The other end of the helical spring is braced against one end surface of a rear (internal) casing part, so that the ferrule is mounted so that it can move axially against the spring force. The fiber sheath extends in central holes of the ferrule-holder and the casing. This design allows the fiber sheath to slide back into the cable sheath and into the strain-relief element when the ferrule slides back, so that the excess fiber length resulting from rearward movement of the ferrule does not lead to impermissibly high bending and kinking stresses on the fiber. In order to protect the fiber from axial tensile stresses, the end of the strain-relief element is fastened by crimping between a rearward extension of the casing and a separate sleeve. The casing must be manufactured of metal in order to absorb the radial forces produced thereby.
The known plug-type connector requires comparatively numerous sleeves, which require separate handling, and production-intensive, expensive metal casing parts and multiple production steps for secure fastening of the strain-relief element end. In a first assembly step the sleeve must be threaded onto the cable and, after the fiber has been immobilized in the ferrule, must be crimped to the extension of the casing.
In a plug-type connector disclosed by U.S. Pat. No. 4,984,865, a central opening of a ferrule-holder is filled with an adhesive or sealant, into which both an optical fiber and its fiber sheath, as well as the ends of a strand-type strain-relief element, are completely embedded. With this design, the ferrule with the optical fiber and the fiber sheath are not axially movable with respect to the strain-relief element.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the present invention is to simplify the manufacture of a plug-type connector with respect to providing strain-relief.
This object is achieved, according to the invention, in a plug-type connector of the aforesaid type, by the fact that the casing has a receiving space for the strain-relief element; that the receiving space is separated in a liquid-tight manner from the central casing opening; and that the strain-relief element can be immobilized at its end in the receiving space by adhesive bonding and/or sealing. A substantial advantage of the invention is that the strain-relief element can be immobilized in the casing without additional individual parts. Adhesive bonding and/or sealing of the strain-relief element replaces crimping, which is problematic in terms of repeatability and exertion of force on the casing. As a result, the casing can be produced from more economical materials. The adhesive or sealant can be applied in advance into the receiving space
REFERENCES:
patent: 4362356 (1982-12-01), Williams et al.
patent: 5052774 (1991-10-01), Bulman et al.
patent: 5058984 (1991-10-01), Bulman et al.
patent: 5091990 (1992-02-01), Leung et al.
patent: 5101463 (1992-03-01), Cubukciyan et al.
patent: 5193133 (1993-03-01), Schofield et al.
patent: 5222169 (1993-06-01), Chang et al.
patent: 5428703 (1995-06-01), Lee
patent: 5436994 (1995-07-01), Ott et al.
patent: 5515466 (1996-05-01), Lee
Healy Brian
Siemens Aktiengesellschaft
LandOfFree
Optical fiber plug-type connector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical fiber plug-type connector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical fiber plug-type connector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-450464