Abstract: A Z-pluggable optical communications module (OCM) is provided that contains multiple parallel OCMs (POCMs) and that is configured to be removably plugged into an opening formed in a front panel of an optical communications system. When the Z-pluggable OCM is plugged in a forward Z-direction into the opening formed in the front panel, an actuator mechanism is actuated to impart motion to the Z-pluggable OCM in the downward Y-direction to cause the Z-pluggable OCM to be mounted on an upper surface of a motherboard PCB. In order to unplug the Z-pluggable OCM, the actuator mechanism is actuated to impart motion to the Z-pluggable OCM in the upward Y-direction to cause it to be dismounted from the motherboard PCB.

Abstract: An optical connector includes a first optical-electric coupling element, a second optical-electric coupling element, and a fixing device. The first optical-electric coupling element defines a first cavity and a second cavity. The second cavity includes two opposite first sidewalls. Each first sidewall defines a locating cutout. The second optical-electric coupling element is received in the second cavity, and defines a third cavity. The third cavity includes two opposite second sidewalls. Each second sidewall defines a through hole. The fixing device includes two elastic deformable portions conforming the two through holes, and a number receiving holes each for receiving a optical fiber. The fixing device is received in the through holes, with the elastic deformable portion resisting against an internal sidewall of the locating cutout, to firmly lock the second optical-electric coupling element into the second cavity of the first optical-electric coupling element.

Abstract: An optical backplane system (600) comprising a horizontal backplane (30), a coupler (33) assembled to the backplane, a card assembly (100), and a connector assembly (500). The horizontal backplane defines a number of positioning holes (306). The coupler defines a number of upward openings (320) and a corresponding number of downward openings (340) upwardly communicating corresponding upward openings through the positioning holes. The card assembly has a number of first optical plugs (26). The connector assembly has a number of second optical plugs (46). When the card assembly and the connector assembly are mounted onto the backplane, the first and second optical plugs are inserted into corresponding openings of the coupler, so that the first optical plug are optically communicated with corresponding second optical plugs.

Abstract: A circuit board assembly includes a substrate, a first optical connector, a second optical connector, and at least two planar light wave circuits. The first optical connector includes a first circuit board electrically connected to the substrate, at least one first laser diode, at least one first photodiode, and a first transparent shell. The second optical connector includes a second circuit board connected to the substrate, at least one second laser diode, at least one second photodiode, and a second transparent shell. The planar light wave circuits are arranged between the first and second transparent shells. Each first laser diode is optically coupled with a second photodiode through a first transparent shell, a planar light wave circuit, and a second transparent shell. Each second laser diode is optically coupled with a first photodiode through a second transparent shell, a planar light wave circuit, and a first transparent shell.

Abstract: An optical module providing higher reliability during high-speed light modulation and a lower bit error rate when built into a transmitter (transceiver). An optical module contains a taper mirror for surface emission of output light, an optical modulator device, and an optical modulation drive circuit, and the optical modulator device and the optical modulation drive circuit are mounted at positions so as to enclose the taper mirror.

Abstract: There is provided an optical engine assembly including an active unit and a transmission unit. The active unit includes a first bearing member configured to carry an optoelectronic unit. The transmission unit includes a second bearing member configured to fix a plurality of optical waveguides. The optoelectronic unit is optically coupled to the optical waveguides. The first bearing member and the second bearing member have symmetrical structures. The present disclosure further provides a manufacturing method of an optical engine assembly.

Abstract: A plug connector for connecting a cable to a receptacle connector includes a housing (209) comprising an upper housing portion (212) assembled to a lower housing portion (211), the assembled portions defining a cavity (280) within the housing. One or more pr ted circuit boards (201, 202) are disposed in the housing cavity and a cable (100) is disposed in the housing cavity and connected to printed circuit boards. The assembled upper and lower housing portions define a first housing sidewall comprising an upper sidewall portion (221u) at the upper housing portion and a lower sidewall portion (221b) at the lower housing portion. The upper and lower sidewall portions define a gap (220-1) in the first housing sidewall at an interface between the upper and lower sidewall portions of the first housing sidewall. The gap extends only partially or at least partially along a length of the first housing sidewall.

Abstract: In an optical connector, a metal case has engageable concaved parts at free ends of side plates; a housing has engageable convexed parts, engageable with the engageable concaved parts, on side surfaces corresponding to the side plates of the metal case; and the engageable convexed parts each have a separation restriction part for restricting the corresponding side plate from being laterally distanced from the corresponding side surface in a state where the engageable convexed parts and the engageable concaved parts are in engagement with each other.

Abstract: A fiber optic and electrical connection system includes a fiber optic cable, a ruggedized fiber optic connector, a ruggedized fiber optic adapter, and a fiber optic enclosure. The cable includes one or more electrically conducting strength members. The connector, the adapter, and the enclosure each have one or more electrical conductors. The cable is terminated by the connector with the conductors of the connector in electrical communication with the strength members. The conductors of the connector electrically contact the conductors of the adapter when the connector and the adapter are mechanically connected. And, the conductors of the adapter electrically contact the conductors of the enclosure when the adapter is mounted on the enclosure.

Abstract: An AOC assembly comprising two printed circuit boards (PCB) (63), a board holder (61) and two dust proof, heat conducting metal covers (64) with integrated head spreader. Each of the two PC boards has a lower edge (632) extending in a longitudinal direction with circuit pads on opposite sides of PCB thereof. The board holder has two opposite vertical datum faces with two of said PC boards respectively positioned thereon. The two heat conducting covers oppositely fixed to the holder in a transverse direction perpendicular to the PC boards. When assembled, the integrated heat spreader of heat conducting metal shell would touch the active electronic components on the PCB and dissipate their excessive heat therefrom.

Abstract: An HDMI signals transmission device includes a first HDMI connector, a second HDMI connector, a first cable, a second cable, and an optical fiber connector assembly. One end of the first cable is electrically connected to the first HDMI connector. One end of the second cable is electrically connected to the second HDMI connector. The optical fiber connector assembly includes a first optical fiber connector electrically connected to the other end of the first cable, a second optical fiber connector electrically connected to the other end of the second cable, a first optical fiber interconnected between the first optical fiber connector and the second optical fiber connector, and a second optical fiber interconnected between the first optical fiber connector and the second optical fiber connector.

Abstract: A plug connector for connecting optical fibers to an electrical receptacle connector includes a housing defining a cavity therein. At least one printed circuit board (PCB) is disposed in the housing cavity. The PCB includes one or more optoelectronic components disposed on its top surface and electrical contacts disposed proximate a mating edge of the PCB for mating with the receptacle connector. The electrical contacts are electrically connected to the one or more optoelectronic components. One or more optical fibers enter the housing cavity through a housing opening and are optically coupled to the optoelectronic components. A structure comprising a top surface is disposed within the housing cavity between the housing opening and the PCB. The plurality of the optical fibers extends over the top surface of the structure and over at least a portion of the top surface of the PCB.

Abstract: An optoelectronic assembly includes a substrate subassembly and a cable subassembly. The substrate assembly includes a substrate, a holder disposed on the substrate, an optoelectronic interface IC, and a plurality of optoelectronic components. The cable subassembly includes a lens cover and a plurality of fiber cables bonded to the lens cover. The optoelectronic interface IC and the optoelectronic components are disposed in a cavity formed by side walls of the holder. The optoelectronic components include at least one laser source and a plurality of photodiodes. The lens cover is inserted into the cavity and thereby fixedly engaged with the holder.

Abstract: An optical module base is made up of a plurality of lead frames and a resin structure integrally molded with the lead frames and has an optical device mounting part and an optical waveguide mounting part which are formed in the resin structure. Each of the lead frames includes a connection part to which an optical device is to be mounted and electrically connected and a lead part which is continuous with the connection part. A portion of the thickness of the connection part is embedded in the resin structure and is positioned at the optical device mounting part. A sufficient strength of fixing a lead frame on a resin structure integrally molded with the lead frame can be ensured even if the sizes of the lead frames are miniaturized according to the sizes of electrodes of an optical device to be flip-chip bonded.

Abstract: An optical-electrical connector assembly comprises a housing, a printed circuit board received in the housing and including a number of converting elements, a lens member, a ferrule aligned with the lens member and having a resisting portion, an integrated securing member, a coiled spring received in the securing member, and an optical cable having a number of optical fibers. The ferrule has a first engaging portion and a second engaging portion engaged with the housing. The coiled spring is compressed between the resisting portion and the first engaging portion.

Abstract: A modular connector infrastructure includes device connector modules having optical connectors to optically connect to respective subsets of electronic devices in a system. The device connector modules are removably connected to the electronic devices.

Abstract: A connector module includes a module optical connector and an engagement member to engage with a device having a device optical connector. The engagement member upon engagement with the device is to cause movement of the module optical connector towards the device optical connector.

Abstract: Chip identification pads for identification of integrated circuits in an assembly. In one example embodiment, an integrated circuit (IC) assembly includes a controller, a plurality of ICs, a shared communication bus connecting the controller to the plurality of ICs and configured to enable communication between the controller and each of the plurality of ICs, and a set of one or more chip identification pads formed on each IC. Each set of chip identification pads has an electrical connection pattern. The electrical connection pattern of each set is distinct from the electrical connection pattern on every other set. Each distinct electrical connection pattern represents a unique identifier of the corresponding IC thereby enabling the controller to distinguish between the ICs.

Abstract: Provided is a compact optical communication module which is configured and structured so as to be suitable for high-speed transmission and which facilitates the fixing and positioning of optical elements and prevents misalignment of the optical axis during temperature change. An optical communication module is constituted so as to have a transceiver circuit as the circuit substrate, a submount unit, a fiber stub as an optical connector member, and an optical fiber coupling member. The optical communication module is configured as a modular component in which the optical axis of an optical element mounted on the submount unit is roughly parallel to the mounting surface of the transceiver circuit.

Abstract: An electro-optical connector assembly includes a first data connector for arrangement on a first device and a second data connector for arrangement on a second device, the first and second data connectors being for communicating data through free space between the first device and the second device and, a first power connector for arrangement on the first device and a second power connector for arrangement on the second device, the first and second power connectors being for providing wireless power transfer between the first device and the second device.

Abstract: An apparatus for providing self-aligned optical coupling between an opto-electronic substrate and a fiber array, where the substrate is enclosed by a transparent lid such that the associated optical signals enter and exit the arrangement through the transparent lid. The apparatus takes the form of a two-part connectorized fiber array assembly where the two pieces uniquely mate to form a self-aligned configuration. A first part, in the form of a plate, is attached to the transparent lid in the area where the optical signals pass through. The first plate includes a central opening with inwardly-tapering sidewalls surrounding its periphery. A second plate is also formed to include a central opening and has a lower protrusion with inwardly-tapering sidewalls that mate with the inwardly-tapering sidewalls of the first plate to form the self-aligned connectorized fiber array assembly. The fiber array is then attached to the second plate in a self-aligned fashion.

Abstract: An optical connector includes a fiber holder to hold optical fibers; a housing to accommodate the optical fibers and the fiber holder; and a thermally driven actuator to displace at least a part of the fiber holder upon application of heat from a first position at which the fiber holder is retracted inside the housing to a second position that allows the optical fibers to be optically coupled to a counterpart connector.

Abstract: An active optical cable is provided that incorporates a power management solution. The AOC has plugs are configured to mate with respective USB sockets. The AOC is used to interconnect a USB host with a USB device. To the USB host and to the USB device, the AOC appears to be a standard USB electrical cable. Each of the plugs of the AOC has an optical-to-electrical and an electrical-to-optical (OE/EO) conversion module that converts electrical USB signals output from the USB host or USB device into optical signals and converts optical signals carried on the optical fibers of the AOC into electrical USB signals. The plugs include controllers that monitor certain conditions of the AOC and that select the power levels to be used in the plugs based on detected conditions.

Abstract: A plurality of flip-chips, each having a plurality of optoelectronic elements formed therein, are flip-chip mounted on a top surface of a substrate that is comprised of a material that is transparent to the operating wavelength of the light produced by optoelectronic elements of the flip-chips. The combination of flip-chips comprises an array of precisely-aligned optoelectronic elements. When the substrate comprising the array of optoelectronic elements is mounted on a PCB, electrical contact pads disposed on the bottom and/or top surface of the substrate are in contact with the respective electrical contact pads disposed on the top surface of the PCB to electrically interconnect the PCB with the flip-chips. Mating features on the substrate that have been precisely positioned by semiconductor fabrication steps are disposed for mating with respective mating features of a multi-optical fiber ferrule device that have been precisely formed in the ferrule device at precise locations.

Abstract: An electronic device with cable includes a circuit substrate, an electrical connector that is connected to one end of the circuit substrate, a cable that is connected to the other end of the circuit substrate, a metal housing that accommodates the electrical connector and the circuit substrate, a first resin housing that engages with the metal housing so as to cover at least a portion of the metal housing, and a second resin housing that engages with the metal housing so as to cover at least another portion of the metal housing.

Abstract: An apparatus includes a connector that connects to optical fibers for connecting first and second optical signals to the apparatus. A first optical ferrule is mounted perpendicularly to the connector, and transfers the first optical signals between the connector and first optical transducers mounted on a first substrate, via first holes formed in the first substrate. A second optical ferrule is mounted perpendicularly to the connector, and transfers the second optical signals between the connector and second optical transducers mounted on a second substrate, via second holes formed in the second substrate. A light rotation module bends and transfers the first and second optical signals between the connector and the first and second ferrules. One or more lenses are mounted between the first ferrule and the first holes, so as to couple the first optical signals via the first holes between the first ferrule and the first optical transducers.

Abstract: An optical module includes a substrate, an optical device of a surface-emitting element or a surface-receiving element mounted on a surface of the substrate with a light-emitting portion or a light-receiving portion located to face the surface of the substrate, an optical fiber disposed parallel to the surface of the substrate and in a longitudinal direction of the substrate, a mirror provided to face the light-emitting portion or the light-receiving portion of the optical device and a tip of the optical fiber, and optically connect the optical device and the optical fiber, and an optical fiber receiving groove provided in the surface of the substrate to receive the optical fiber. A width of the mirror is greater than a width of the optical fiber receiving groove. Reflecting portions are provided on edges, respectively, of a mirror side end of the optical fiber receiving groove, and the reflecting portions reflect incident light from the mirror facing the edges, again back to the facing mirror.

Abstract: This document discusses, among other things, a connector for an optical imaging probe that includes one or more optical fibers communicating light along the catheter. The device may use multiple sections for simpler manufacturing and ease of assembly during a medical procedure. Light energy to and from a distal minimally-invasive portion of the probe is coupled by the connector to external diagnostic or analytical instrumentation through an external instrumentation lead. Certain examples provide a self-aligning two-section optical catheter with beveled ends, which is formed by separating an optical cable assembly. Techniques for improving light coupling include using a lens between instrumentation lead and probe portions. Techniques for improving the mechanical alignment of a multi-optical fiber catheter include using a stop or a guide.

Abstract: An optical connector includes a jumper, optical fibers and an optical-electric coupling element. The jumper includes a first side surface and a second side surface. A locating flange extends from the first side surface. The locating flange includes a first vertical surface. The jumper defines receiving holes through the first and second side surfaces and the first vertical surface. Each of the optical fibers is received in a respective receiving hole. The optical-electric coupling element includes a third side surface defining a locating cavity. The locating cavity includes a second vertical surface forming coupling lenses. The locating cavity also includes a lower sidewall and an upper sidewall defining an opening. The second vertical surface is substantially perpendicular to the upper sidewall. The locating flange is inserted into the locating cavity, with each coupling lenses aligned with a respective optical fiber.

Abstract: An optical module, including a PCB, an optical component arranged on the PCB, and an optical fiber coupled with the optical component through an optical lens module, further including a fixed bracket, a lens bracket detachably connected with the fixed bracket, and a fiber bracket detachably connected with the lens bracket, the fixed bracket is fixed on the PCB, the optical lens module is arranged on the lens bracket, the optical fiber is arranged on the fiber bracket, and the optical component is located between the fixed bracket and the lens bracket, the fixed bracket is provided with at least two positioning parts, the lens bracket is provided with positioning parts matching respectively the positioning parts of the fixed bracket to achieve detachable connection. The optical path coupling is achieved through the mechanical fixation among multiple brackets, working process is simplified, and coupling consistency and accuracy are improved.

Abstract: A receptacle block defines one or more sockets at which plugs may be received. Each socket contains a first set of contacts and a second set of contacts. Each socket also includes a sensing contact that interacts with the second set of contacts to close an electrical switch. For example, the sensing contact can interact with an arm extending from one of the contacts of the second set. Closure of the switch can be detected and interpreted to indicate that a plug has been received at the respective socket.

Abstract: The invention provides a package structure of optical connector, comprising: an input circuit board, an output circuit board, a flexible circuit board, an optical transceiver module, and an enclosure for packing the above components. The input/output circuit board comprises a connecting terminal and an input/output terminal comprising a plurality of input/output ports, wherein the input circuit board and the output circuit board are fixed by the two opposite sides of the enclosure to create a specific space between the input circuit board and the output circuit board. The flexible circuit board is electrically connected to the connecting terminal of the input circuit board and/or the connecting terminal of the output circuit board. The optical transceiver module is electrically connected to the input circuit board and the output circuit board. The enclosure comprises an electrical connecting opening and an optical connecting opening corresponding to the electrical connecting opening.

Abstract: An optical fiber coupler includes a clad optical fiber core having a coupling window formed therein. A laser source is joined to emit light into the core through the coupling window. The core has an output coupler for partially reflecting a portion of light and transmitting a portion as output. A Bragg grating is formed in the core having a pitch and being positioned to reflect light from said laser source toward the output coupler. The pitch is variable in response to a temperature change. A thermal control device is joined to the core for adjusting its temperature and the Bragg grating pitch. In other embodiments a mode convertor is provided to reduce the output modes to selected modes.

Abstract: An optical finger navigation device and method for making the device uses a light pipe array lens, which includes an array of light pipes formed in a monolithic block of material. The light pipe array lens is configured to function similarly to a fiber bundle lens to transmit light through the lens using the light pipes in the monolithic block of material.

Abstract: An apparatus is provided and includes a housing, a block formed to define an array of holes corresponding to an array of plugs into which connectors with spring loaded sleeves are pluggable such that the block engages with a respective sleeve of each connector, the block being supportively disposed within the housing to be movable with respect to the housing between first and second block positions at which the sleeves are extended and retracted, respectively and a cam lever supported on the housing and coupled to the block, which selectively occupies first and second lever positions at which the cam lever causes the block to assume the first and second block positions, respectively.

Abstract: An cable assembly (100) includes an insulative housing (1); a first terminal module (21) and a second terminal module (22) assembled to the insulative housing, the first terminal module (21) having first terminals (212a) and first additional terminals (212b), the second terminal module (22) having second terminals (222a) and second additional terminals (222b); a photoelectric conversion device (93) electrically connected with the first terminals and the second terminals; and a cable (6) including fiber wires (63) and copper wires (61), the fiber wires optically connected to photoelectric conversion device, the copper wires electrically connected to the first additional terminals and the second additional terminals.

Abstract: Methods, apparatuses, and systems related to optical connector assemblies are described. In some embodiments, the connector assemblies may include an optical assembly, having an optical interconnect and an optical module, to be coupled with a host electrical connector. The connector assembly may further include springs, disposed on the optical interconnect or the host electrical connector, to facilitate a coupling of the optical interconnect with the optical module. Other embodiments are described and claimed.

Abstract: An optical fiber assembly includes two adapters and a connecting element. Each of the adapters includes a connector, a first coupling portion, and a first optical fiber connected between the connector and the first coupling portion. The connecting element includes two second coupling portions and a second optical fiber connected between the two second coupling portions. The second coupling portions are detachably connected to the first coupling portions.

Abstract: An electronic device includes a board including an electronic component, a plurality of optical interface units that include an optical element which input or output light and that are provided on the board, and a plurality of individual positioning units that position a plurality of respective optical waveguides which are separate from each other at least at tip portions on a side of the optical interface units and which are optically aligned with the optical element with respect to the optical interface units independently from each other.

Abstract: In one embodiment, an optical transceiver assembly includes an active component substrate, first and second fiber securing devices, and a holder device coupled to the active component substrate. The holder device includes an active optical component recess that encloses a first and second active optical component of the active component assembly, and first and second fiber-locating holes having an engagement feature at the active optical component recess such that an end of first and second fibers inserted into the first and second fiber-locating holes are aligned with the first and second active optical components along the x-, y-, and z-axes. In another embodiment, an optical component assembly includes an active component substrate having a solder ring, a fiber securing device, and an active optical component on the active component substrate. The fiber securing device is aligned with the active optical component by the solder ring.

Abstract: An isolator comprising: a first semiconductor substrate including a first electrical circuit; a second semiconductor substrate including a second electrical circuit; and at least one optical waveguide for data exchange between the first and second electrical circuits.

Abstract: A photoelectric converter includes a laser diode, a female optical transmission module, a male optical transmission unit, and a photo diode. The female optical transmission module includes a plurality of first lenses and a plurality of second lenses oriented at ninety degrees from each other, with total internal reflection between the two lenses. The female optical transmission module defines a detection cutout, from which the first lenses and the second lenses can be observed simultaneously. The photoelectric converter has a high reliability in signal transmittance.

Abstract: An optical transceiver capable of narrowing an extra space for an external optical fiber is disclosed. The optical transceiver of an embodiment provides an optical receptacle with a port, to which the external optical fiber is to be inserted, headed for a direction in diagonal to the longitudinal axis of the optical transceiver. In another embodiment, the optical transceiver provides an optical receptacle capable of turning the port thereof.

Abstract: The present invention provides an optical module and an optical system that can form a two-way optical transmitting and receiving line with the same optical wiring configuration without using any special parts. The optical module includes a plurality of single-fiber optical adapters, a multi-fiber optical adapter, a plurality of single-fiber optical connectors mating with the respective single-fiber optical adapters, a multi-fiber optical connector mating with the multi-fiber optical adapter, and a plurality of optical fibers connecting the respective single-fiber optical connectors and the multi-fiber optical connector. Wiring of the optical fibers is configured to connect two single-fiber optical connectors inserted into adjacent single-fiber optical adapters and fiber holes in the upper tier and the lower tier in the same row of the multi-fiber optical connector.

Abstract: For providing circuit arrangement and method for transmitting signals from a data source to a data sink, the signals being TMDS encoded, the driver circuit is supplied by a connection interface, connected upstream, assigned to data source, with supply voltage, electrical TMDS encoded signals are electro-optically converted by an LED connected downstream of the driver circuit and coupled into an optical fiber as light supplied with TMDS encoded signals, the direct current portion supplied from TMDS transmitter to connection interface, to data source, is converted by driver circuit to a modulated signal current for controlling LED.

Abstract: A pluggable optical transceiver is disclosed. The transceiver comprises a plurality of OSAs, an optical member and a plurality of inner fibers to couple the optical member with OSAs. The inner fibers each provides an inner connector to couple with one of OSAs. The housing, which installs the OSAs, the optical member and the inner fiber, is made of metal and has a grooves into which the inner fibers is set so as to arrange them orderly.

Abstract: A pluggable optical transceiver is disclosed. The transceiver comprises a plurality of OSAs, an optical member and a plurality of inner fibers to couple the optical member with OSAs. The inner fibers each provides an inner connector to couple with one of OSAs. The housing, which installs the OSAs, the optical member and the inner fiber, is made of metal and has a grooves into which the inner fibers is set so as to arrange them orderly.

Abstract: A connector for connecting a fiber optic cable to a light source comprising a female adaptor having a receiving bore and a channel projecting into the receiving bore; a male ferrule, having a first portion insertable into at least part of the receiving bore, and a second portion defined at least partially by a tapered diameter region; and a compressible ring member disposed in the channel that engages the tapered portion when the male ferrule is inserted in the female adaptor in order to provide some resistance to removal of the male ferrule from the female adaptor.

Abstract: An interposer, comprising: (a) a planar substrate having top and bottom surfaces, the bottom surface defining at least one ferrule alignment structure, and fiber bores, each bore hole being in a certain position relative to the ferrule alignment structure and adapted to receive a fiber; (b) at least one ferrule having an end face and comprising one or more fibers protruding from the end face, and at least one alignment feature cooperating with the ferrule alignment structure to position the ferrule precisely on the bottom surface such that the fibers are disposed in the fiber bores and protrude past the top surface; and (c) at least one optical component having one or more optical interfaces and being mounted on the top surface such that each of the optical interfaces is aligned with one of the fiber bores and is optically coupled with a fiber protruding from the fiber bores.

Abstract: A connector defining a receiving space for receiving a corresponding plug, comprises a first housing, a second housing retained to the first housing along a back to front direction, and a plurality of contacts retained in the first housing and the second housing. The first housing has a first base and a first tongue forwardly extending into the receiving space. The second housing has a second tongue jointing with the first tongue along the back to front direction to form an integral tongue plate. The integral tongue plate has a volume which is same to that of the first tongue. A front end surface of the first tongue is located at front of a front end surface of the second tongue along a front to back direction.