Abstract:
An optical fiber connector by which a worker can easily connect optical fibers at an on-site location, and in particular to an optical fiber connector which makes it possible to prevent the problems that an adhered state of a ferrule optical fiber installed in a ferrule is broken owing to a bending phenomenon occurring when an elastic member ferrule moves within an allowable (set) movement range owing to the nature of elastic force member or a connected state of a fusion connection part is damaged.

Description:
RELATED APPLICATION 
       [0001]    The present application claims priority from Korean Patent Application No. 10-2011-0121356 filed Nov. 21, 2011 in the Korean Intellectual Property Office, which is hereby incorporated by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to an optical fiber connector by which a worker can easily connect optical fibers at an on-site location, and in particular to an optical fiber connector which makes it possible to prevent the problems that an adhered state of a ferrule optical fiber installed in a ferrule is broken owing to a bending phenomenon occurring when an elastic member moves within an allowable (set) movement range owing to the nature of elastic force or is a connected state of a fusion connection part is damaged. 
       BACKGROUND ART 
       [0003]    In recent years, a fiber to the home (FTTH) system is provided so as to provide various information including broadcast and communication information by connecting an optical fiber to ordinary homes. The system is widely installed in an apartment and a house. In the above mentioned FTTH system, an optical fiber is connected to a home in such a way that the ends of the optical fiber are finished with an optical fiber connector. Here, a FTTH worker prolongs an optical fiber up to a home by setting the optical fiber a couple of meters longer than an actually needed length in consideration of the connection between the optical fibers. In addition, the worker cuts an optical fiber by the length that is needed for a corresponding home which becomes an on-site location, and assembles an optical fiber connector at each end of the optical fiber, and the assembled optical fiber connector is connected to an optical adaptor and is finally installed at the home. 
         [0004]    Various technologies on the above-mentioned optical fiber connector to connected to the optical fiber connector are described in the following patent documents: Korean patent registration publication number 10-0669947; Korean patent publication number 10-2009-0078350; Korean patent publication number 10-2009-0083373; Korean paten publication number 10-2007-0045972; Japanese patent publication number Hei 2009-69607; Japanese patent publication number Hei 2008-225461; and Korean patent registration number 10-1038195. 
         [0005]    When connecting the ends of the ferrule optical fiber installed at the ferrule with an adhesive and the ends of the main optical fiber, the conventional optical fiber connector is connected by a mechanical connection method which uses a main cable alignment member configured to accommodate the ends of the ferrule optical fiber and the ends of the main optical fiber as disclosed in the in-site assembling type optical fiber connector of Korean patent registration publication number 10-0669947 or a melted connection method which reinforces the melted connection part with a reinforcing sleeve formed of a shrinkable tube after the ends of the ferrule optical fiber and the ends of the main optical fiber are melted and connected using an optical fiber melting connector (refer to Korean patent publication number 10-2009-0083373; Korean paten publication number 10-2007-0045972; Japanese patent publication number Hei 2009-69607; and Japanese patent publication number Hei 2008-225461). 
         [0006]    The present invention is directed to a melted connection method. The optical fiber connector using the above mentioned melted connection method, as shown in  FIG. 1 , comprises a ferrule  1  including a ferrule optical fiber, an elastic member  2  elastically supporting the ferrule, a plug frame  4  accommodating the ferrule and the elastic member, a stopper  3  installed at the plug frame and fixing the ferrule and the elastic member at the plug frame, a reinforcing sleeve  5  configured to reinforce the ends of the ferrule optical fiber and the melted connection part of the ends of the main optical fiber, a plug handle  6  and a boot  7 . 
         [0007]    The optical fiber connector of the melted connection method features in that the ferrule is elastically supported by the elastic member, and the elastic member  2  moves within an allowed movement range. In the event that the ferrule moves within a range that the elastic member allows, the adhered state between the ferrule body  1   a  and the ferrule optical fiber  1   b  might be damaged or the ferrule optical fiber might become short circuit, and a ferrule optical fiber portion  1   b ′ might be bent. 
         [0008]    As shown in  FIG. 1   b , when the ferrule moves within the range that the elastic member  2  allows when an external force is applied, the portion  2   b ′ of the ferrule optical fiber  1   b  between the ferrule body  1   a  and the reinforcing sleeve  7  is bent, and the frequent movements of the ferrule body  1   a  makes defective the adhered state between the ferrule body and the ferrule optical fiber, and the ferrule optical fiber might become short circuit. When the external force is applied to the ferrule body  1   a , part of the ferrule optical fiber is bent, and part of the short ferrule optical fiber is bent, which means that the bent angle is great, so the efficiency of the optical fiber is lowered. 
         [0009]    In the optical fiber connector of the conventional melted connection method, when the melted connection part is reinforced by heating the reinforcing sleeve formed of the shrinkable tube, the deformation might occur as the adhesive used so as to integrally connect the ferrule body and the ferrule optical fiber melts, so when assembling the optical fiber connector, it is needed to minimize exposure of the ferrule to heat. 
         [0010]    As the exposure of the ferrule to heat is minimized, a cold peeling (room temperature) is mainly performed when peeling the coating of the ferrule optical fiber. At this time, a greater force (load) is applied to the ferrule when peeling the coating of the ferrule optical fiber, so the adhered portion of the ferrule is damaged, and the ferrule optical fiber may short circuit (disconnection). 
         [0011]    The problems of the conventional art will be described with reference to the above-mentioned patent documents. 
         [0012]    The optical fiber connector disclosed in Korean patent publication number 10-2009-0083373 is directed to a compact size. The structural ferule  7  and the reinforcing (sleeve) sleeve  15  are arranged closer to each other, so the adhesive used for integrally connecting the optical fiber to the ferule might be deformed by the heat when heating for the sake of the heat shrinkage of the reinforcing (arc) sleeve. 
         [0013]    The optical fiber connector disclosed in Japanese patent publication number Hei 2008-225461 is directed to forming a protruded portion at the fixture engaged to the frame while making sure that the tensional force is enhanced so that it can integrally engage when the reinforcing sleeve is thermally contracted. When the reinforcing sleeve is thermally contracted and is integrally formed at the protruded portion of the structural fixture, the fixture and the optical fiber of the ferrule are integrated by the reinforcing sleeve. As shown in  FIG. 1 , when the force (load) is applied to the front ferrule of the connector, the ferrule moves in a longitudinal direction of the optical fiber by means of the elastic member. At this time, as shown in  FIG. 1   b , the portion  1   b ′ of the ferrule optical fiber  1   b  having a short length is bent (curved), so the optical fiber might be cut resulting in a short circuit or it might be bent at a great angle, so the loss ratio might be greatly increased. 
         [0014]    The optical fiber connectors of Korean patent publication number 10-2009-0083373; Japanese patent publication number Hei 2009-69607; Japanese patent publication number Hei 2008-225461 have features in that the optical fiber is peeled at the factory and is assembled to the ferrule using the adhesive and is cut and supplied to the on-site location. If it is supplied with the coating unpeeled, the ferrule optical fiber made by adhering the ferrule and the optical fiber using an adhesive might have a weakened strength at the adhered portion due to the peeling load when peeling at the on-site location, so it is impossible to overcome the deformation and short circuit problems. 
         [0015]    As the optical fibers are peeled, adhered, cut and supplied to the on-site location for the sake of the ferrule in the factory, it is hard to handle which results in the increased manufacture cost, and the short circuit might occur during the handing at the on-site location. 
         [0016]    In addition, the peeled optical fibers are exposed long in the air, so they might be contaminated by moisture or other contaminants. 
         [0017]    As a method for improving the above mentioned problems, Japanese patent publication number Hei 2009-69607 provides a packing technology so as to provide the peeled optical fiber of the ferrule. In the event that they are packed and supplied, the manufacture cost might be increased, and the whole volume of the packed product increases, so the costs needed for the transportation increases. 
         [0018]    The reinforcing sleeve  5  as shown in  FIG. 2  is adapted to the conventional optical fiber connector and comprises a dual tube formed of two thermal shrinkage tubes of an outer tube  5   a  and an inner tube  5   b  and a metallic reinforcing pin  5   c , so the thermal shrinkage takes long due to the dual tube during the heating for the sake of thermal shrinkage. 
         [0019]    In order to improve the above mentioned problems, the applicant of the is present application provided the optical fiber connector of Korean registration number 10-1038195 and the optical fiber connector made by the assembling method of the same as shown in  FIG. 3 . 
         [0020]    In case of the optical fiber connector of the patent registration number 10-1038195, the ferrule can move in the longitudinal direction of the optical fiber when an external force is applied by means of the elastic member, so the reinforcing sleeve configured to reinforce the melted connection part might be bent. The optical fiber connector of the patent registration number 10-1038195, as shown in  FIG. 1 , can improve the problems that the cut losses and the increased loss ratio increase as it is bent at a great angle; however as the reinforcing sleeve is frequently bent, the cut losses or the increased loss ratio still occur. 
       SUMMARY 
       [0021]    Accordingly, an embodiment of the present invention is made to improve an embodiment of the optical fiber connector of Korean patent registration number 10-1038195 of the same applicant as the present application while improving the problems encountered in the conventional art and it is an aspect of the present invention to provide an optical fiber connector having features in that it is possible to overcome the hard handling and increased unit cost problems which occur as the ferrule optical fibers are supplied unpeeled and are peeled at an on-site location and are assembled while making sure that the ferrule optical fiber can be bent at a great angle at the portions of the ferrule or the melted connection portions can be bent, thus preventing the cut losses and increased loss ratio which occur due to the bending. 
         [0022]    In addition, it is another aspect of the present invention to provide an optical fiber connector featuring in that as the structure is simple, the worker can work easily, and as the number of the elements decreases, the manufacture cost decreases, so it is possible to supply the products at lower costs. 
         [0023]    First of all, to achieve the above objects, there is provided an optical fiber connector in which a ferrule optical fiber accommodated in a ferrule elastically supported by an elastic member and a main optical fiber are melted and connected using a melted connection part, and the melted connection part is reinforced by a reinforcing sleeve, thus connecting the main optical fiber and the ferrule optical fiber, which comprises a ferrule bush which is disposed between the ferrule and the elastic member, one end of the ferrule bush being engaged with the reinforcing sleeve when reinforcing the melted connection part; and a boot which is installed at an outer side of the reinforcing sleeve and is connected with the ferrule bush. 
         [0024]    Second of all, to achieve the above objects, there is provided an optical fiber connector in which a ferrule optical fiber accommodated in a ferrule elastically supported by an elastic member and a main optical fiber are melted and connected by a melted connection part, and the melted connection part is reinforced by a reinforcing sleeve, thus connecting the main optical fiber and the ferrule optical fiber, which comprises the ferrule and a ferrule bush and the ferrule optical fiber which are integrally formed; and an elastic member which is disposed between the ferrule bush and a guide stop ring, with an end portion of the ferrule bush or an end portion of the ferrule optical fiber passing through the guide stop ring and being integrally engaged with the reinforcing sleeve. 
         [0025]    The ferrule bush has a through hole into which is inserted part of the enlarged tube formed at the ferrule optical fiber of the ferrule, so the ferrule bush and the ferrule are separated or the ferrule bush is assembled integrally with the ferrule. 
         [0026]    An end portion of the ferrule bush or an end portion of the ferrule optical fiber passes through the guide stop ring and is integrally engaged with the reinforcing sleeve. 
         [0027]    The main optical fiber is clamped by a clamp cap installed at a boot installed at an outer side of the reinforcing sleeve reinforcing the melted connection part. 
         [0028]    An engaging part having at least one protruded groove is formed at an end portion of the ferrule bush, and the engaging part is installed surrounding an end portion of one side of the reinforcing sleeve, so the ferrule and the reinforcing sleeve are integrated. 
         [0029]    The ferrule bush can move in a longitudinal direction of the optical fiber by means of the guide stop ring, and the rotation of the ferrule bush is fixed in the axial direction of the optical fiber. 
         [0030]    The ferrule optical fiber is supplied in the type of a ferrule assembly, and it is supplied in such a way that the coating of the ferrule optical fiber is not peeled so that the end portions of the ferrule optical fibers can be peeled at an on-site location, and the ferrule bush in the construction belonging to the ferrule assembly is engaged with the reinforcing sleeve reinforcing the melted connection part. 
         [0031]    The optical fiber connector according to an embodiment of the present invention has features in that the plug frame accommodating the ferrule and the elastic member is not connected with the boot, and the ferrule bush installed at the ferrule is connected with the boot. When the elastic member is compressed by the external force, the plug frame and the plug handle move in the direction of the ferrule (the left or forward direction in the drawing) which is the direction opposite to the boot, so the optical fiber is not bent by the movement of the ferrule, and it is possible to prevent the problems which occur due to the bending of the optical fiber. 
         [0032]    In addition, two elements of the ferrule and the ferrule bush disclosed in the optical fiber connector of Korean patent registration number 10-1038195 of the same applicant as the present invention are integrated into one element, so the assembly becomes simplified during the manufacture and use, and the manufacture cost and the product price can be lowered. 
         [0033]    The foregoing and other aspects will become apparent from the following detailed description when considered in conjunction with the accompanying drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0034]      FIG. 1  is a partially assembled cross sectional view of a conventional optical fiber connector, of which (a) is a cross sectional view illustrating an engaged state, and (b) is a cross sectional view illustrating a phenomenon that part of the ferrule optical fiber is bent when an external force is applied to the ferrule. 
           [0035]      FIG. 2  is a view illustrating a reinforcing sleeve in the construction of a conventional optical fiber connector, of which (a) is a perspective view, and (b) is a cross sectional view. 
           [0036]      FIG. 3  is a cross sectional view illustrating an operation state of a conventional connector provided from the same applicant as the present invention, of which (a) is a partial cross sectional view illustrating an engaged state of an optical fiber connector, and (b) is a partial cross sectional view illustrating an optical fiber connector when a force is applied to the ferrule in a longitudinal direction of an optical fiber in an engaged state. 
           [0037]      FIG. 4  is a disassembled perspective view illustrating an optical fiber connector according to an embodiment of the present invention. 
           [0038]      FIG. 5  is a disassembled view of an optical fiber connector according to an embodiment of the present invention. 
           [0039]      FIG. 6  is an assembled cross sectional view illustrating an optical fiber connector according to an embodiment of the present invention. 
           [0040]      FIG. 7  is a cross sectional view illustrating a ferrule assembly and a reinforcing sleeve and a boot which are parts of the construction of an optical fiber connector according to an embodiment of the present invention while showing a construction before the ferrule assembly and the boot are assembled. 
           [0041]      FIG. 8  is a cross sectional view illustrating a ferrule assembly and a reinforcing sleeve and a boot which are parts of a construction of an optical fiber connector according to an embodiment of the present invention while showing a construction after the ferrule assembly and the boot are assembled. 
           [0042]      FIG. 9  is a disassembled perspective view illustrating an optical fiber connector according to another embodiment of the present invention. 
           [0043]      FIG. 10  is a disassembled perspective view illustrating an optical fiber connector according to another embodiment of the present invention. 
           [0044]      FIG. 11  is a cross sectional view illustrating a ferrule assembly and a reinforcing sleeve and a boot which are parts of a construction of an optical fiber connector according to another embodiment of the present invention while showing a construction before the ferrule assembly and the boot are assembled. 
           [0045]      FIG. 12  is a cross sectional view illustrating a ferrule assembly and a reinforcing sleeve and a boot which are parts of a construction of an optical fiber connector according to another embodiment of the present invention while showing a construction after the ferrule assembly and the boot are assembled. 
           [0046]      FIG. 13  is an assembled cross sectional view illustrating an optical fiber connector according to further another embodiment of the present invention. 
           [0047]      FIG. 14  is a perspective view illustrating a reinforcing sleeve of a construction of an optical fiber connector according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0048]    The preferred embodiments of the present invention will be described with reference to the accompanying drawings. The terms and words used in the specification and claims should not be limitedly interpreted as they are from the conventional dictionary, but should be interpreted as the meaning and concepts matching with the technical ideas of the present invention based on the principle that the inventor can most properly define the concepts of the terms so as to describe his invention in the best way. 
         [0049]    So, the embodiments and constructions defined in the specification of the invention mean the most preferred embodiments of the present invention, while not representing all the technical concepts of the present invention, and they should be interpreted as there might be various equivalents and modifications which could substitute such things at the time of filing the present invention. 
         [0050]    As shown in  FIGS. 4 and 6 , the optical fiber connector “C” of an embodiment of the present invention comprises a ferrule optical fiber  11  adjacent to a ferrule  10 , a ferrule bush  15  surrounding the ferrule optical fiber  11 , an elastic member  20  configured to provide an elastic force as it is installed at an outer side of the ferrule  10 , a plug frame  30  configured to accommodate the ferrule  10  and the elastic member  20 , a guide stop ring  40  fixing the ferrule  10  and the elastic member  20 , a connector handle  60  accommodating the plug frame  30 , a reinforcing sleeve  50  reinforcing the ferrule optical fiber  11  of the ferrule  10  and a melted connection part of the main optical fiber  80 , and a boot  70  installed at the outer side of the reinforcing sleeve  50  and connected with the ferrule bush  15  installed at the ferrule  10 . 
         [0051]    As shown in  FIGS. 4 to 8 , the ferrule  10  has a through hole at the inner side in which is installed a ferrule optical fiber  11  and a diameter enlargement part  12  is installed at one side of the same. The ferrule optical fiber  11  and the diameter enlargement part  12  are integrated with the ferrule  10  using an adhesive. 
         [0052]    The above described construction shares select aspects with the optical fiber connector of Korean patent registration number 10-1038195 and the ferrule which is used in the conventional art. 
         [0053]    There is provided a guide ferrule bush  15  accommodating the diameter enlargement part  12  installed at one side of the ferrule  10 . The ferrule bush  15  has a step profile at an outer side of the same thus supporting a coil spring which is the elastic member  20 . At the other side is provided a guide part  15 - 1  passing through the guide hole  42  formed at the guide stop ring  40 , and at the end portion of the guide part  15 - 1  is provided an engaging part  15 - 2  having at least one protruded grove in which is installed the reinforcing sleeve  50  provided so as to reinforce the melted connection part. At the outer surface of the guide part  15 - 1  is provided at least one plane part  15 - 4 , and at its end portion is provided an engaging protrusion  15 - 3  for the sake of an engagement with the boot  70 . 
         [0054]    The engaging part  15 - 2  allows the ferrule bush  15  and the reinforcing sleeve  50  to be integrated. 
         [0055]    As shown in  FIG. 14 , the engaging part  15 - 2  might not be formed at the ferrule bush  15 . In other words, the engaging part  15 - 2  is not formed at the ferrule bush  15 , so the reinforcing sleeve  50  can be connected to only the ferrule optical fiber  11 . 
         [0056]    The plane part  15 - 4  comes into contact with the plane part formed at the inner surface of the guide hole  42  of the guide stop ring  40  which will be described later, thus allowing the ferrule bush  15  to move in the longitudinal direction of the ferrule optical fiber  11  while not permitting a rotation about the ferrule optical fiber  11 . 
         [0057]    As shown in  FIGS. 7 and 8 , the engaging protrusion  15 - 3  formed at the outer surface of the ferrule bush  15  is inserted into the engaging groove  70 - 1  formed corresponding to the engaging protrusion  15 - 3  at the end portion of the boot  70 , so the ferrule bush  15  and the boot  70  are engaged. 
         [0058]    The ferrule optical fiber  11  is protruded while passing through the ferrule bush  15  to make sure that one end can be positioned at the ferrule  10 , and the other end can melt and connect with the main optical fiber  80 , and the protruded end portion is provided with its end unpeeled, so it is peeled at the on-site location. 
         [0059]    The ferrule bush  15  features in that it can prevent the portion adhered by the adhesive from being damaged by the heat in such a way to lower the heat which is transferred from the ferrule  10  during the heating process when the ferrule optical fiber  11  is peeled or the reinforcing sleeve is installed. 
         [0060]    As shown in  FIGS. 4 to 8 , the elastic member  30  is made from an ordinary coil spring and is installed at an outer surface of the guide part  15 - 1  of the ferrule bush  15 . 
         [0061]    As shown in  FIGS. 4 to 8 , the plug frame  30  has an engaging groove  31  so as to accommodate one side of the ferrule  10  at the inner side and the ferrule bush  15  and the elastic member  20  and so as to be engaged with the guide stop ring  40  which is inwardly inserted, and an engaging protrusion  32  is provided at the outer side so as to be engaged with the connector handle  60 . 
         [0062]    As shown in  FIGS. 4 to 8 , the guide stop ring  40  features in that its one side is inserted into the plug frame  30 , thus supporting the ferrule  10  and the ferrule bush  15  and the elastic member  20  which are accommodated in the plug frame  30 . At its outer side is provided an engaging protrusion  41 , and at its inner side is provided a guide hole  42  having a plane part for the sake of a rotation prevention. 
         [0063]    The engaging protrusion  41  is engaged to the engaging groove  31  of the plug frame  30 , thus fixing the ferrule  10 , the ferrule bush  15  and the elastic member  20  which are accommodated in the plug frame  30 , and the plane part formed at the guide groove  42  comes into contact with the plane part  15 - 4  formed at the guide part  15 - 1  of the ferrule bush  15  which passes through, while making sure that the ferrule bush  15  can move in the longitudinal direction of the ferrule optical fiber  11  and it cannot rotate about the ferrule optical fiber  11 . 
         [0064]    As shown in  FIG. 8 , the reinforcing sleeve  50  is configured to reinforce by surrounding the melted connection part which the ferrule optical fiber  11  and the main optical fiber  80  are connected. As shown in  FIG. 14 , the reinforcing sleeve  50  is formed of a single tube type formed of the thermal shrinkage tube  51  and the thermal adhering layer  52  made from a thermal adhesive such as a hot melt at the inner side of the thermal shrinkage tube  51  and might include a reinforcing pin which has an elastic force and can be bent. A reinforcing sleeve having an ordinary metallic reinforcing pin can be used. 
         [0065]    As shown in  FIG. 7 , the reinforcing sleeve  50  thermally shrinks when it is installed at the melted connection part to which are connected the ferrule optical fiber  11  and the main optical fiber  80 , and heat is applied thereto, thus surrounding in an integrated shape the melted connection part to which are connected the ferrule optical fiber  11  and the main optical fiber  80 . 
         [0066]    The single tube type reinforcing sleeve  50  having the thermal adhering layer  52  at its inner side can seal the melted connection part of the ferrule optical fiber  11  and the main optical fiber  80  with the aid of the thermal adhering layer  52  when heating it. 
         [0067]    The connector handle  60  accommodates the plug frame  30  which accommodates the ferrule  10 , the ferrule bush  15  and the elastic member  20  and has at its inner side an engaging groove corresponding to the engaging protrusion  32  formed at the outer side of the pug frame  30 . 
         [0068]    As shown in  FIGS. 7 and 8 , the boot  70  is engaged with the ferrule bush  15  and surrounds the reinforcing sleeve  50 . As shown in  FIGS. 4 and 5 , an engaging groove  70 - 1  is provided so as to engage with the engaging protrusion  15 - 3  formed at the ferrule bus  15 , and at an end portion of it is provided a cut-away portion  70 - 2  at a peripheral portion of the engaging groove  70 - 1 , thus providing an elastic force to the engaging groove  70 - 1 , so the engaging protrusion  15 - 3  formed at the ferrule bush  15  can be easily engaged to the engaging groove  70 - 1 . 
         [0069]    At the end portion (the side which the main optical fiber is inserted into) opposite to the portion where the ferrule bush  15  is connected might be provided a clamp device  71  for the purpose of clamping the main optical fiber  80 . 
         [0070]    The clamp device  71  comprises a clamp part  72  which is formed at an end portion of the boot body and the diameter of which changes when an external force is applied, and a pressurizing ring  73  which is installed at an outer side of the clamp part  72  and applies an external force to change the diameter of the clamp part  72 . 
         [0071]    The clamp part  72  has at least one cut-away portion at the end portion for its diameter to change when an external force is applied, and at its inner side are provided a plurality of clamp protrusions so as to enhance the clamping power. 
         [0072]    The pressurizing ring  73  has a taper (slope surface) at the inner surface so as to apply an external force by which the diameter of the clamp part  72  can change. 
         [0073]    At an outer surface of the clamp part  72  is formed a male screw groove, and at an inner surface of the pressurizing ring  73  is formed a screw groove, so the clamp part  72  and the pressurizing ring  73  can engaged with each other in a to screw engaging way. 
         [0074]    The assembling procedures of the optical fiber connector “C” according to an embodiment of the present invention will be described. 
         [0075]    As shown in  FIG. 7 , into the plug frame  30  are accommodated the ferrule  10 , the ferrule bush  15  and the elastic member  20 , and the guide stop ring  40  is engaged, and the ferrule  10  in which is installed the ferrule optical fiber  11 , the ferrule bush  15 , the elastic member  20 , the plug frame  30  and the guide stop ring  40  are engaged, thus forming an integrated type ferrule assembly. 
         [0076]    The ferrule assembly is featured in that the ends of the optical fiber  11  peeled at the on-site location using an optical fiber melting device and the main optical fiber  80  are melted and connected and reinforced with the reinforcing sleeve  50 . 
         [0077]    As shown in  FIG. 6 , the ferrule bush  15  of the ferrule assembly and the boot  70  are engaged using the engaging protrusion  15 - 3  of the ferrule bush  15  and the engaging groove  70 - 1  of the boot  70 , and in the event that the clamp device  71  is formed at the boot  70 , the main optical fiber  80  is clamped using the clamp device  71 . 
         [0078]    The assembled optical fiber connector “C” of the present invention, as shown in  FIG. 8 , features in that a bending phenomenon does not occur at the ferrule optical fiber  11  or the main optical fiber  80  or the portion of the optical fiber of the melted connection part reinforced by the reinforcing sleeve adhered to them. When the elastic member  20  is compressed, the plug frame  30  integrally fixed with the guide stop ring  40  and the connector handle  60  moves in the leftward direction when viewing from the drawing. 
         [0079]    In other words, as the ferrule bush  15  of the ferrule assembly and the boot  70  are engaged, when the elastic member  20  is compressed as an external force is applied, the optical fiber portion positioned at the inner side of the optical fiber connector “C” is not bent, and the stop ring  40  the plug frame  30  and the connector handle  60  can move in the leftward direction when viewing from the drawing. 
         [0080]    As the bending phenomenon does not occur at the optical fiber portion positioned at the inner side of the optical fiber connector “C”, it is possible to overcome the problems which used to occur in the conventional art. 
         [0081]    When the ferrule  10  is supplied to the ferrule assembly, the relatively smaller elastic member  20  and the guide stop ring  40  might not be lost while peeling the end portions of the ferrule optical fiber  11  by the worker at the on-site location. 
         [0082]      FIGS. 9 to 12  show another embodiment of the present invention. 
         [0083]    As shown in  FIGS. 9 to 12 , the optical fiber connector “C” of another embodiment of the present invention comprises a ferrule  10  in which is integrally installed a ferrule optical fiber  11 , a ferrule bush  15 , an elastic member  20  installed at an outer side of the ferrule  10  so as to provide an elastic force, a plug flame  30  accommodating the ferrule  10  and the elastic member  20 , a guide stop ring  40  engaged to the plug frame  30  for fixing the ferrule  10  and the elastic member  20  accommodated in the plug frame  30 , a connector handle  60  accommodating the plug frame  30 , a reinforcing sleeve  50  reinforcing the melted connection part of the ferrule optical fiber  11  of the ferrule  10  and the main optical fiber  80 , and a boot  70  which is positioned at an outer side of the reinforcing sleeve  50  and is connected with the ferrule bush  15  installed at the ferrule  10 . 
         [0084]    As shown in  FIGS. 9 to 12 , the ferrule  10  has a through hole at an inner side for the purpose of installing the ferrule optical fiber  11 , and at its one side is installed the guide ferrule bush  15 . 
         [0085]    The ferrule optical fiber  11  and the ferrule bush  15  are integrated with the ferrule  10  using an adhesive. 
         [0086]    As shown in  FIGS. 4 to 8 , in the optical fiber connector “C”, the diameter enlargement part  12  is provided at the ferrule  10 , and the ferrule bush  15  is installed at the diameter enlargement part  12 ; however in the optical fiber connector “C” of another embodiment as shown in  FIGS. 9 to 12 , the diameter enlargement part  12  is removed from the ferrule  10 , and the ferrule bush  15  is directly installed at the ferrule  10  while functioning as the diameter enlargement part  12 . 
         [0087]    The ferrule bush  15  has a step profile at an outer side thus supporting the coil spring which is the elastic member  20 , and at the other side is provided a guide part  15 - 1  passing through the guide hole  42  formed at the guide stop ring  40 , and at an end portion of the guide part  15 - 1  is provided an engaging part  15 - 2  having at least one protruded groove in which is installed the reinforcing sleeve  50 , and at an outer surface of the guide part  15 - 1  is formed at least one plane part  15 - 4 , and at an end portion is provided an engaging protrusion  15 - 3  for the sake of an engagement with the boot  70 . 
         [0088]    As shown in  FIGS. 11 and 12 , the engaging protrusion  15 - 3  formed at an outer surface of the ferrule bush  15  is inserted into the engaging groove  70 - 1  formed corresponding to the engaging protrusion  15 - 3  at the end portion of the boot  70 , so the ferrule bush  15  and the boot  70  are engaged. 
         [0089]    The ferrule optical fiber  11  is protruded while passing through the ferrule bush  15  in such a way that its end is positioned at the ferrule  10 , and it other end can be melted and connected with the main optical fiber  80 . In the protruded end portions, the ends are provided unpeeled, so they are peeled at the on-site location using the peeling device. 
         [0090]    Since the remaining constructions given the same reference numerals as the optical fiber connector “C” of  FIGS. 4 to 8  are same as the construction of the optical fiber connector “C” of  FIGS. 4 to 8 , so they will be not described. 
         [0091]    Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.